How to calculate maximum demand charge from appliance wattage

Update: Use this plan to mine bitcoin or other cryptocurrencies.

Beware: sharp spikes

This billing scheme is covered with sharp spikes.  It'll be practically impossible for average consumers to comply with the rules, because even if you're really trying, one misstep in a month can spike your bill $35 or $70.  "for no conceivable reason".   Only consider this type of billing if you have automatic systems which force you to comply with the plan's rules.

It's yet another dodgy way to package energy costs

In the last decade you've probably been flooded with offers to change how you buy electric or gas.  (partly because of deregulation.  One common scheme with gas was to "fix" your rate "to protect you from gas company increases" - actually fracking was pulling gas prices down.  Those companies made a mint.

All these plans are gambling. (in fairness, so is staying put).  But this you know: They wouldn't be offering these plans unless their expert industry opinion was they'd make more money if they do.  Since it's a zero-sum game, that means you lose.  And indeed, they often pay hefty commissions to salespeople, with door-to-door salespeople making $0/hr and $200/sale.

Historically most people pay 8 to 15 cents per kwh per power.  In this deal, you pay an exorbitant monthly rate for your peak use for the month ($6.64 per kw); then electricity is practically free (1c/kwh) all hours except summer/fall weekday air conditioning times (10c/kwh).  They are betting your usage is spiky.  You are betting your usage is flat.  But they have all your smart-meter data.  You don't.

The business rationalization for this plan is it charges you for the "thickness of the wire" needed to deliver to your home.  But wait. The service lateral is already plenty big, and they're not going to downgrade you to #8 and upgrade you to #6 or #4 if you pay enough peak charges.  If this applied to neighborhoods, wouldn't it only apply at times neighborhoods normally have peaks?  How does it hurt the grid if you blast dryer, EV charger and on-demand shower at midnight when the neighborhood pipe is wildly underused, and the nuke plant is giving power away? Why should that define your peak?   This rationalization simply makes no sense.

The only way you can win under this plan is to become a master of your energy usage, particularly your peaking. If  you can master your household peaking, it's a very good deal.  But people are awful at that.  You can't rally a modern family to be that conscientious.  It's totally impractical and the industry knows that.  That's the scam.  You get a $300 energy bill and the stage is set for them to flip it around and make it your fault.

Plans like this are common for commercial power delivery, but business/government have a  Facilities department whose job is to manage onsite power consumption and contain costs.  Families do not.

A 2790 watt dryer does not exist

Gas dryers take around 500 watts give or take, just for the drum and fan. Electric dryers on a 30A circuit (7200 watts) are allowed a maximum of 80% (5760W) so they try to run near the max, or about 5500 watts.  There are no dryers in the range of 2000–3500 watts.  Why did the power company choose an obviously wrong number in the middle of the dead zone?  They're averaging all dryers, gas and electric.

Keep in mind a 5500W element is undersized compared to what manufacturers want, but it's limited by the 30A dryer circuit.  (Contrast with gas dryers, where manufacturers face no such restriction). Gas dryers are much faster IME.

Similarly, the linked website understates or omits many other peak loads.  It does not claim 2790W, which makes me skeptical of the source of this.

Your actual loads

Remember, a "KWH" is a kilowatt for an hour.  Your dryer might use 5500W = 5.5KW, and if you run that for 30 minutes, that's 2750 WH = 2.750 KWH.  Peak load is concerned with KW, not KWH.

The power company may already have your 30-minute peak load (from your smart meter).  It may already be stated on your electricity bill.  Or you could try calling the customer service department (certainly not the Sales department!) Either way, look at the last 24 months.

Which begs the question: why are they soliciting you for this rate?  Did they look at your statements and see that they'll make more money that way?

If your smart-meter displays instantaneous KW (remember this is not KWH), that can help - you can just walk out there and check it "live". Try turning on every single thing you have even a small probability of using all at once: cooktop, dryer, max the A/C, blast the hot water, and see what the meter tells you is your current instantaneous KW.   Multiply that by $6.64, that will be almost all your electricity bill every winter month when power is essentially free on this plan.  Just to armwave:

3000W for various 120V loads.
5500W for the dryer (30A)
5500W for air conditioner (30A)
5500W for an electric hot water heater on a 30A breaker
3500W for a couple burners on the stove

If you think a perfect storm is unlikely, consider cooking.  Washing dishes, making a lot of heat in the kitchen which the A/C must work harder to remove... this loads all of the above, except the dryer.

So I see 23000W or 23kw peak, or @$6.64 about $152 monthly.

That's just for the monthly peak-usage fee.

It could be even worse in the winter, if you had electric heat. A typical 8-foot baseboard is 2000 watts, with shorter baseboards proportional.

There will also be the cost of the electricity proper: close to zero most of the time, and normal price during peak air conditioning hours 2–7pm M–F Jun-Sep.  That part of the deal is quite generous.

But your peak loads are murder.  An ideal house that draws 2000W continuously (the way the nuke makes it), would cost $37/mo.** under this plan, $94 in the summer months (less if it was smarter).

** $10 monthly fee, $13 peak fee, $14 energy usage

The same, more realistic house that averages 2000W and peaks at 20,000W would cost $157*** in winter, and $213 in summer.

*** $10 monthly fee, $133 peak fee, $14 energy usage

Turn the tables

I personally think humans are too fallible.   One false move — dry while cooking once — and your bill leaps $34.  The best plan is to add some technology that makes compliance automatic and human-proof. At the least, interlocks to keep you from running appliances at once.  At best some "smart home" technology that auto-throttles appliances in a sequence — cooktops > hot water > A/C > dryer etc.

First, you can't work blind.  You have to actually know your moment-by-moment usage.  Install a home-energy monitor like Neurio, Aeotec or Curb into your house.  These put sensors inside your service panel, which clip to the L1 and L2 "hot" wires.  They come up on your phone or tablet and give you rich displays about what your energy usage is.  They can even pick out individual appliances based on their electrical noise.

Bigger picture, it's a huge opportunity to architect smart systems that automate much of this.  Even more could be done with heat storage — have a large insulated water tank in the backyard, and all night, your heat-pump chills it with cheap midnight power, and by day, you use it to air-condition your house much more efficiently.  All this leads to a "smart grid" where the power company can do load-management, i.e. tell your dryer to stop heating for a minute so they can avoid having to spin up an expensive peaker.

Guess who pays for this tech.

If they could actually get people to do this sort of thing, then this plan would make sense for the grid. But where is the PR campaign explaining to consumers how to do this?  If it exists, it's pretty feeble, isn't it?  They don't profit when people are smart, they profit when people are stupid.

Ironically, their rate punishes peaking, but doesn't reward conservation.  Those annoying 24×7 "vampire loads" that the rest of us are stomping out?  Not your problem.  They lavishly reward you for consuming energy off-peak: mine bitcoins, grow medicinal herbs or pot, whatever. Consider 5000W of grow lights, rigged to shut off at peak summer hours or when you are running dryer, water heater, A/C or kitchen.  It adds nothing to your peak usage fees, and you pay <1 cent per kwh.  Crazy. Crazy.  They are literally giving power away.

Do exactly that: Bitcoin

Since I wrote this, we have been flooded with almost daily inquiries for people trying to wire up Bitcoin miners, which take an impressive amount of electricity and so a cheap electric rate is key.  I keep thinking about this rate.  You can't avoid peaks, but you can have the Bitcoin miners working very hard in all the valleys for a penny a KWH. You would need some sort of power line monitoring to have the miners "back off" when you start the dryer so they do not heighten the peaks.  The hardware for that isn't that hard to find.

Why on earth

Easy: your area is over-nuked.  Nukes provide base-load. They run 24×7 full throttle, stopping only for fuel changes (and fuel is dirt cheap). So they have a glut of midnight power — they literally can't give it away. (this video here, after 10:09). Meanwhile they're starved for peakers, because they're spending all their money on more nukes at $7/watt (for political reasons) instead of useful peakers like turbines and solar (for a fraction). So they have to clip the peaks, and they're using punitive rate charges to do it.

Trouble is, consumers won't understand why the rate punishment, won't have the tools (energy monitor) or knowledge to change their behavior, and will just get exploited.  A swindle indeed.


Temperature in Condo hotter than thermostat setting- Gas Furnace

I ended up having to call the furnace repairman. It turned out that the gas valve was stuck in the open position, leading to the overheating issue.


Bearing wall: probably not.
Structural wall: possibly.
I suspect the floor joists run parallel to the wall you want to remove. If no overhead loads bear on this wall, then it’s not a load bearing wall.
However, the wall could support (brace) the exterior wall.
If the wall does not have plywood on it, it probably is not a structural wall. The Code requires the width of a building to be a certain percentage of the length. If it exceeds (less than 1:4, I think) that amount, an interior wall (bracing) be added for shear.


You can try filing the broken piece out with a Dremel tool with a sanding drum attachment but I've had little luck doing that. You're better off just cutting out the junction and installing a new one with three repair sleeves. Good luck.


60-minute Drywall for ceiling beneath residential fire sprinklers?

I doubt you need a 1-hour Fire rated ceiling.

Fire sprinklers eliminate the need for fire rated construction in wood frame buildings, unless 1) encroachment on property line setback requirements, 2) hazardous storage facility, 3) fire separation between an occupancy type “I” (institutional) and other occupancies.

Also, it may be required under local sub-division requirements (CC&R’s).

However, fire ratings are based on SYSTEMS. if you need a 1-hour fire rated SYSTEM, you can use: 1) 5/8” Type “X” on the ceilings with joists spaced up to 24” oc, or 2) 1/2” Type “C” gypsum board on the ceiling with joist spacing up to 16” oc.  If you need to space the framing further apart than 24”, you can add stripping, but nailing is critical...I’d check with the local Building Official.

Remember, nailing size, type and spacing is critical.


Laundry drain smells like sewer after washing clothes

How can I determine if the sewer smell is from a lack of p-trap in the wall (ideally without removing drywall)?

It would be very unlikely for there not to be a trap; they are required by code. More likely you have a trap that is being siphoned dry, which can be caused by various problems including poor venting, clogged or partially clogged drain, poor design.

Could the sewer smell come from another clog?

YES... well not really coming from another clog, but caused by a clog or partial clog.

could I just put a p-trap outside of the wall attached to the plate to solve the smell?

NO you can't piggy-back traps. If there is a trap in the wall (and I would bet $5 that there is) you can't install an additional trap.
I would recommend that you ensure that all house drains are running free and clear (by whatever means necessary) and same with all vents. The fact that you merely wet-vacced the line and did not snake the drain line (


How to remove a concrete-filled, steel bollard

Use (if you can fit it on) or replicate the function of a "lally column cutter" - I suspect replicate the function will be the better bet - use a cutoff disk in an angle grinder to score a line around the base of the steel (not a piddly little score, ideally - deepish, but it need not hit concrete) and then smack the top of the column. Enjoy the power of "stress concentration" as the steel snaps at the score-line, and the concrete will go with it.

Be sure that your new structure provides adequate protection to whatever you are building a structure over (I'm gathering the hydrant is an example, not the actual thing) if being plowed into by a vehicle remains an issue; which presumably is why there are bollards there in the first place.


Why can't I find a listed single pole dual smart switch?

I'd use Insteon for this job
The type of control flexibility you want with multiple controlled devices at a single wallstation isn't really addressed by "smart switches" per se, as the programming becomes involved enough that a single, standalone "smart" wallbox control with that functionality is no longer worthwhile.  Instead, what you get into at that level are systems of lighting control, designed for complex situations where entire sets of lights can be controlled with a single button. While there are a variety of products that can handle the duty, most require special low-voltage control wires from the wallstations to a central control unit, which rules them out in a retrofit like this.  However, the Insteon system uses a mix of power-line and wireless communications that lends itself well to retrofits, and also has a FanLinc module available for precisely the job you are after; namely, controlling a fan and its associated lights (or a different set of lights) simultaneously.
In this situation, I'd use an Insteon keypad module connected to always-hot and neutral at the wallbox, while bringing that same always-hot and neutral up to the fan.  At the fan, a FanLinc module is wired, much the same way you'd do with any other fan remote receiver; this gives you full dimming control over the connected lights, as well as multi-speed control of the fan.  You can also replace the existing wallbox dimmer with an Insteon dimmer and make all the lights in the room "talk", allowing for one-button scene control of both light sets from the same keypad that handles the fan.  Of course, all the Insteon gear is properly listed and labeled -- Insteon was in the "smart" game well before all the consumer-gadget vendors jumped on the bandwagon.


Diagnosing low faucet flow: Single faucet

Do you have a screen, in the tap (faucet) at the end where water comes out into the sink?  (or the line that collects hard lime, water deposits?) This can be a problem anytime the water is hard, THUS quite mineralized. Those bits- often the size of sand grains -- can collect and wreak havoc. Clogging of water lines if galvanized via mineral build up before getting to the faucet in the supply lines can be an issue also. I have seen this in laundry lines where mixed water is a problem when washers do not rinse well - their lines are messed up with sand, pet hair and other clothing debris that does not rinse out of the filter properly and collects to clog everything up, one must check the washers as well as the mesh screens at ends of supply lines so all water goes where it should without a hitch - or leave linty residue on clothing because of the clogs involved.


If you have to do this from below then you need to remove a large section of drywall such that you can secure the metal housing for the fan to supports.  Once you need to cut a large section of drywall you might as well mark the joists and cut back to 1/2 the width of the closest joist and remove from one joist to the other, for the other dimension whatever makes sense and add some nailing edges.

Ultimately you'll need to tape, mud, sand 4 edges and buy a full sheet of drywall.  A little extra length to the taping isn't going to change much.  You'll also need to paint for this kind of thing you might as well paint the whole ceiling.

Since you've indicated there is an attic above depending on your climate you'll have to patch or install vapor barrier and do a good air sealing especially in a bathroom.


Tempered Glass Tabletop - Safe dimensions for a given base?

If you use only four support points, your glass top is actually sitting on a square about 2.12 feet on each side. So your overhang for a 4 foot circle is about 11 on each side.

Tempered glass is very strong (note that annealed or hardened glass is also strong, but much less so than tempered). This calculator suggests that a 1/2" tempered glass shelf 11" x 25" supported at the ends would withstand a weight of over 600 lbs. The pressure on your table edge is somewhat different, since it is supported only along one edge, but that edge is attached to the rest of the top. It sounds as if there is little danger of the unsupported edge breaking off.

The bigger risk is tipping. If someone leaned on the edge of the top in between two of the support points, you have a lever of about 1 foot lifting three fee of tabletop. The top would be quite heavy (maybe 80+ lbs.) and would take a lot of pressure to tip. But it is quite possible, say if someone sat on the edge.

Consider adding several more support points around the edge (at least 4 more).  This would increase the supported area to nearly 3 feet, and reduce the unsupported section to just over 6 inches.


"6" is a #6-size screw. Screw gauges are a measure of the head size and shaft size, and are roughly linear but not quite a 1:1 relationship (a #8 screw is a little less than twice the diameter of a #4 screw). There isn't a good system for converting gauge to a calibrated measurement, so you're best off consulting a table like this: http://hingedummy.info/screwinfopage2.htm

Screws have three basic measurements: gauge, threads per inch, and shaft length in inches. So, you may also see a measurement like 6-32 x 1 1/2". This means it's a #6 diameter, with 32 threads per inch (almost double the normal thread count as a standard wood screw) and an inch and a half long. When the middle number is absent (6 x 1 1/2"), the screw has the "normal" number of threads per inch for that size and type of screw (for #6 wood screws that's 18).


Reverse osmosis water saddle doesn't fit waste pipe

I ran into a similar situation and not being able to locate the correct sized part (saddle) I successfully installed a hose barb fitting

Looking at your photo I can't easily find an acceptable location for a threaded barb fitting. Ideally it should be oriented vertically and on top of any pipe section. And obviously before the trap.
If it's possible to add a short extension of pipe to the connection where the flexible hose is attached so as to allow an attachment point that would facilitate connecting the new fitting.
Installation is a simple matter of drilling a slightly undersized hole and forcefully turning the fitting into it after wrapping the threads with Teflon tape.


Quartz is a man-made product of natural stone components in a resin binder.   It is almost as heat resistant as granite (but the resin can be damaged) but is significant more stain resistant than granite.  It is not porous and does not have to be sealed as natural stones do.

That said, you should wipe up spills quickly with regular detergent and take reasonable care.  You're going to have to find out the actual manufacturer of your countertops to get an specific care recommendation, but there is no lack of generic sources on the internet.

https://www.bobvila.com/articles/how-to-clean-quartz-countertops/


Will painted wood that has been buffed to a polished finish remain so with daily use, i.e. a desk?

With the type of prep and finish you are describing it sounds like the desk our Dad made for his masters project. It still is in use today by my little brother in his home office, the only difference is you have to know how to open the secret drawers and those can be hard to find , never made it to that level because I went into the sparky world , any time a good sanding and many coats of quality finish is used it can last generations. I love DA or dual action sanders I have found to make high end quality finishes a very fine paper is used , dad taught me to use up to 1200 wet paper for custom jobs with varathane on oak & walnut that looks like glass 20 years later.


What is the difference between swage fittings and compression fittings?

Part of the confusion is 'compression' is sometimes applied to fitting types that are not truly compression type. The term should only be applied to fittings where the compressive force is is applied by screw threads via part of the fitting itself as opposed to compressive force being applied by external tools.

In this compression fitting, via the threads seen on the right of the left hand piece and inside the right hand piece, the tapered ring on the copper tube is compressed, squeezing the tube tightly such that leakage is not possible. Plastic tube variants have an additional insert piece that fits in the end of the tube so it does not collapse under the compressive force.
This is an example of a crimp fitting. The ring is slipped loosely over the tube before pushing the tube onto the barbed fitting.

An external tool is used to apply the compressive force to the crimp ring. The material properties of the crimp ring are plastic, so that when the tool is removed, the ring continues to apply significant compressive force on the tube. Note that this tool is carried in the field to facilitate on-site assembly of piping systems.
A swage fitting is yet another type. It is similar to a crimp fitting in that an external tool is used to apply pressure and a sleeve maintains the pressure after the tools is removed.

The major difference is the compressive tool applies much much more force to the sleeve than a crimp tool. A swage tool is typically not very portable and not used in the field. Rather, pipes are pre-fabricated in a shop with a heavy duty hydraulic machine. The types of fittings swaged to pipes typically allow field assembly using common mechanic's tools.


Suggestions for a replacement garage door opener

you won't find pricing suggestions here. pricing recommendations become out of date too quickly.

in my experience, if you're looking for smooth operation then you need to concentrate on the door. make sure it opens and closes smoothly. a bad garage opener will still open a well-adjusted door smoothly, but a good opener won't help a poorly adjusted door.

that being said, i really love my genie screw drive. they make a couple of models that open the door 2-3 times faster than it closes.


How to salvage this ruined wall so it can hold paint?

Assuming you have fixed the water problem (if not, give up), why not simply attach drywall directly to the entire surface. You may be able to adhere it with construction adhesive.  If not, use screws, if necessary, with anchors behind them. If it is available, consider moisture resistant drywall or even paperless.

You can then put on any surface finish you want.


How to relocate 50 amp hot tub wires from PVC conduit into ceiling joists

6/3 NM-B is not wire, it is cable.  Cables contain multiple wires.  NM is fine for running through ceiling joists in dry areas where the cable will be protected.  If water is involved in any way, you need UF cable.

Cable can be run through conduit, but only if you are a masochist.  It will be a rather difficult pull.  You will need much larger conduit, because the conduit fill is calculated by looking at the widest dimension of the flat cable, and imagining a round wire that diameter.

There's an exception that allows this imaginary wire to fill most of the conduit if it is the only cable in the conduit. But that only makes it an even more difficult pull, and paints you into a corner as far as any future use of that conduit.

You cannot unsheath cable and use the individual wires.  That is because the individual wires do not have individual wire markings to disclose their type and grade of insulation, and generally their insulation is not tough enough to survive any type of use outside a junction box.  They are allowed as short pigtails entirely inside junction boxes.

If you find cable whose interior wires are marked as some sort of wire that is legal for use in that application, then have a field day.  This is rare but not unheard of, talk to your local electrical supply.

You cannot do a continuous run with new wire because you cannot use loose wires in through-joist wiring.  You need to either fit conduit in the joists, or use some sort of cable rated for such use.

If you run all metal conduit, that is one less wire you need to carry, as the metal conduit serves as the ground wire.

Before you decide on the romance of continuous wire runs, count your bends. More than 360 degrees of bend between access points is illegal. More than one makes pulling exponentially harder.

It is very easy to build a conduit route that is so difficult to pull that you end up needing to call a professional to do it.  Professionals don't like doing a small part of the work, and will want a big chunk of the total job.  Access points are the key to avoiding this, but of course, access points are the enemy of "a finished look" for some reason.  I don't know why, the Victorians had no trouble fitting adorable cabinets where utility access was needed.  It is a 20 minute job to change my tub faucet. Really.


Ok - when unmounting the thermostat, I noticed the manufacturer's name (Danfoss), and from that I was able to find the valve type, which is Danfoss RAVL


Wiring Ecobee thermostat to Vulkan gas furnace with no C terminal

This line:

is the equivalent of the "C" terminal.  Get it from here:


When installing new stud in existing frame, does the stud have to be the *exact* height of the inside of the frame?

For the sistered stud, it makes no difference. All the load is transfered to the adjacent stud and there won't be any movement if you use enough screws and the adjacent stud is properly installed.

For the other side, just make sure the stud is resting firmly against the base plate and screw it down, leaving any slack between the stud and top plate. If there's too much movement, either cut a new stud or put a shim up there. But since none of this is load bearing (in terms of the structure, not your drywall), there's no need for the cuts to be perfect. Just make sure that once installed and screwed in, there isn't any play in the stud, and you'll be fine.


Dry walls nail pops and wall cracks in ceiling doors and windows

Nails popping up above the surface is a common event and usually isn't cause for alarm. The reason this occurs is from slight movement of the framing members (due to expansion and contraction) that over time works the nail loose. Conversely, if the pops and cracks have appeared in a relatively short period of time, it may be time to search more closely for a structural problem. Where I live earthquakes and tremors are common. This quickens the loosening of nails.
Your crawlspace and the framing lumber in it look to be in good shape. This is pretty rare for a house built in the 1940's. I would guess it had some work done not to long ago. If so there might be settling issues that are causing movement.
I can't offer an answer for the dripping noise from your duct/vents. If it is the sound of dripping water it would be wise to verify the problem and repair it soon.
Hammer the pops back in slightly below wall surface. Than screw a 1 5/8 inch drywall screw about 2 inches above the pop. Screws hold better. apply joint compound, let dry, sand, and paint.


It is not safe to operate the bulbs in the wrong sized socket. The loose connection can produce arcing which will cause heating of the connection and could very well lead to fire.

There really is not a practical way to safely replace the pins either. Even though some LED models may appear that it would be possible to solder on different pins I would advise against it. And it is likely that you would either damage the pin attachment points or that obtaining the correct materials ends up costing nearly as much as just getting the proper bulbs.

Safety should not be supplanted by frugality. Get the proper product for the application. Return the product if possible as suggested by Tester101 in the comments. If not returnable then eat up your mistake as a bad investment and learn from it to look more closely at what you select for purchase.


Why isn't the "C" or Common wire working on my Nest thermostat?

The Nest is colorblind.  It has no idea what color your wires are.  The cutesy little Nest screen will show wire colors, but it's wild-guessing based on commonly used wire colors.  In this example, the W wire might actually be brown, the G could be orange.

The wire colors on the display mean nothing.

There is no official color code for the C wire, since it wasn't traditionally used in thermostats.  You can use any color, as long as that wire isn't being used for something else.

The essential thing is that the C wire connects to the 24V side of the transformer, on the terminal which is not the one the R wire goes to.

Connecting C and R to the same terminal of the transformer would do nothing, and the Nest display would probably show C as not connected.

Whatever the Nest display is indicating about the "Blue" wire is irrelevant.  It doesn't know or care what color you are using for the C wire.  Blue is not an official color for the C wire, actually Blue and B are commonly used to switch a heat pump from heat mode to cool mode.  If you don't have a heat pump and the wire color is unused in your cable, steal it for C.

See also Nest's page.


What's the best tool for cutting holes into duct work?

STEP ONE
Using a big flat screwdriver orienteded edgewise and a hammer. Strike the screwdriver swiftly and accurately to puncture the duct.

STEP TWO
Insert a Red pair of snips into the hole and nibble around turning to the left (Greens are pictured only because that's what was in front of me) in an expanding circle until you get to the line.

STEP THREE
Cut along your line all the way to the corner, with force turn and continue while gently pulling up on the scrap. Every 2-3 inches turn in off the line and make a relief cut and go back to the line. Once you get to the next corner you don't need relief cuts anymore.

COMPLETE THE CUT
Now it's easy, just cut along the line gently pulling up the scrap. If you are left handed, or only have greens feel free to use Greens but reverse the images. Yellows are designed to cut straight but are capable of cutting to the left like Reds
FOR CIRCULAR HOLES
The same process applies just without the relief cuts.


Can I use end terminal connectors instead of twist type connectors?

There are all kinds of terminals but if you use the quick-disconnect type that will be better than a wire nut if you're disconnecting and reconnecting at times.

If the wires are inside an enclosure, you could also use a terminate the wire with ring or spade terminals and a terminal block / terminal strip the right size, which is sometimes nice because you can put a meter on the screws in the terminal strip when testing.


How do I change lights bulbs that are 20 feet off the ground and pointing up (in a vanity fixture)?

If you don't want to get an 20' extension ladder (which can be very difficult to transport home from the store), then you can get one of the  Little Giant or Werner multi-ladders:

Or you can get the werner folding ladder:

But, a good ladder will pay off in more ways than just this - cleaning gutters, etc.


Additional receptacles on 20 amp service using quick holes on back

That type of outlet is what we call screw-and-clamp (or I stubbornly call it screw-to-clamp).  Here's a great page comparing the two.

There is nothing wrong with screw-and-clamp. The only caveat I have from the rare times I've dealt with them, is set your torque correctly. Undertorquing will make the wire(s) pop right out when you shove it into the box.

Using the word "quick" to describe screw-and-clamp is something I strongly discourage, because the trade name for that other thing is "Quick-Wire".

(For some reason, manufacturers are reluctant to use our preferred pejorative, backstab, for the jab-and-forget-until-half-the-circuit-goes-dead-for-no-reason types).

In the early days, UL approved backstab connections which were dual-rated for #14 and #12 wire. But these had problems and they were forced to backpedal from that, because the cheap springs (4 for 50 cents) didn't have the range to grip both wires properly.  (also, accepting #12 copper also meant #12 aluminum could fit, and #12 aluminum is legal in 15A circuits, but that copper-only termination couldn't support it.  This is made worse by copper-clad aluminum being out there, forcing you to look at the wire end to determine type).

One time I was running a dehumidifier and the plug felt warm.  That shouldn't be.  The socket was warmer. So I popped it open and found a #12 stranded wire shoved into the backstab. 1/3 of the strands just splayed all over the place.   Stranded wire is a great application for screw-and-clamp, because it helps unraveling to super-twist the wires, and that's a lot easier to do on a straight wire than a shepherd's hook.


Trying to work out existing light switch wiring with possible loop

Not a direct answer, but a way to clue you in if nobody else comes
  along with an answer:

I had to diagnose the wiring on my house when I first moved in. What I did, I first turned off the power on the circuit, then after being sure it was off, I connected a little 9V battery across two wires.

I had my wife stand at the other light switch, and with a multimeter (or voltmeter) check the wires to find which two I was holding in my hands. If you find +9V, the wire contacting the positive lead of the multimeter is the wire touching the positive side of the battery. If you find -9V, the wire contacting the positive lead of the multimeter is the wire touching the negative side of the battery.

If you identify all your wires, and what goes to where, you can make sense of it by drawing a diagram.


How tight should threaded brass pipe fittings be?

As a general rule, fittings with tapered pipe threads (NPT) should not be assembled to a specific torque because the torque required for a reliable joint varies with thread quality, port and fitting materials, sealant used, and other factors. (Source: Parker Hannifin Catalog 4300 Port End Assembly, page T7)

Leakage path through NPT threads occurs between the very peaks of one thread and the very valley of the opposing thread. No matter how tight you make NPT threads, a leakage path still exists. It is the function of the sealant to block the path between the male and female thread.

This is most helpful!

Most screwed piping is tightened until it feels "right" and the fitting is pointing in the desired direction. What the experienced mechanic is often "feeling" is how the fitting is getting tight. Screw it into until it starts to seat. Then up the force a little by yanking. If each yank gives less movement, you probably have a sound joint. If the movement stops suddenly, you have probably bottomed out. The experienced plumber knows when to stop before he damages the fitting or boss. Caution is advised, tapered pipe fittings into an aluminum boss as excessive torque can crack the boss. This is especially true when using Teflon tape because the low friction of Teflon makes it easy to over-tighten.


Can insects get into a house through the ducting?

They can come in with you, on your clothes in or on bags etc.

Unless you have an airlock entry system with strip and new clothes etc.

They will also come in through any gaps and there are few constructions that are 100% sealed. There are tests that can be done to check this.

As for vents they are easy routes for insects, unless there are grilles or filters on each vent which have to be fitted properly - any gap and they get through.

As for HVAc, that depends on the system, if there is a heat exchanger to prevent outside air and inside air from mixing then insects cannot cross but if the outside air is heated or cooled and there is no filter or the filter is damaged or poorly fitted then insects can get through.


Pressure washing is the best way to clean the roof. I would also use a cleanser, such as FLOOD (picture below). Very safe and will do a wonderful job. Safety should be your biggest concern. Make sure you point the force of the spray downward (toward the gutters) to prevent any leaking. Also, don't hold the wand too close to the shakes or you can damage them or cause a lot of weird discoloring. Try to maintain the same distance from the roof all over. About 12-16 inches should be sufficient. Also remember to use the wide fan tip and not the thin stripping tip.

Your maintenance person was most-likely referring to the chemical treatment that is on your shakes. Those need to be redone every 5 years or so. The shakes themselves should last 30-40 years if properly maintained.

Regarding the chemical treatment, there are many different types of treatments and sealants to consider. Careful though, because some will damage copper flashing and can kill vegetation. Make sure the roof is completely dry before you apply anything.


That's built as solid as my parents' driveway. As a walkway, I'd say it's solid and probably ready for use now, but curing it for the additional 4 days could make it more durable and less likely to chip and spall later.

A friend's neighbor poured a 3" thick dog run, then let his dog on it the next day. He later poured an additional 3" slab of the same construction, but kept it wet for 10 days. The fresh slab cracked and chipped within 2 years. The cured slab didn't show a mark even 5 years later.


Is it ok to twist THHN together before installing in conduit?

Electricians never purposely twist wires together before installing them. As a matter of fact, we attempt to keep large conductors separate as they are pulled into the conduit so they do not twist around each other.

First, it is completely unnecessary for identification we just number the neutrals or tag them with some colored tape to indicate which phase conductor they go with.

Second, by twisting the conductors you are filling up more of the conduit and you are shortening the conductor. Using more wire to accomplish your purpose without a clear advantage is wasteful.

Third, the EM fields cancel out anyway without twisting. The reason Cat 6 cable is twisted is to reduce external signal transfer to the wire pairs not for EM cancellation between the pair.

Focus your time on something more productive.

Good luck and stay safe!


Permanent wiring of external flood light from a garage ceiling outlet without conduit: code check

Surface mounting of ceiling wiring is allowed by code but looks DIY and some will think it’s not code even though it is. The only thing you mention is the wire size of #14 for this to be code compliant the circuit breaker protecting the circuit will need to be 15 amp other than that it could be ok.


The messing part is a compression fitting and the chrome part a seal fitting. Tape does not solve your problem. If the compression fitting is leaking you need to replace the ring. If the seal fitting is leaking, turn off the water and disassemble the two parts. Thereafter you would be able to see where it is leaking. Anyway I propose to replace both the compression ring and the seal.


Would increasing the size of the A/C duct for my kitchen improve cooling?

Given that this question is 3 years old you probably moved on... But I can make a couple of non-expert suggestions...

The first thing I would look at is shade. Can you add some foil into the windows to cut down the heat in the morning? Or some shade cloth on the outside? I have large sliding doors facing west and in the summer I span some 50% black shade cloth from the eave to the ground about 6' out. One can see through quite fine and it cuts down the heat load tremendously (even with the low-e windows I have). This saves a lot of money too...

WRT your specific question, here is what I would do. I you want to go to a ceiling register, check out https://www.hvacquick.com/products/residential/Grilles-Registers/Curved-Blade-Grilles/TRUaire-A303-Series-Triple-Deflection-Curved-Blade-Grilles
Click on the links tab and then on the performance data link. You get a table that shows grille size on the left and then performance data across the row keyed by CFM. Take a 10x10 grille, assume you have 200CFM, that means the air "jet" will reach 12ft horizontally ("throw"), and the noise is "NC 30", which is low (there's no lower entry in that table, but other types of grilles/manufacturers go down to NC 20).

Now the other two interesting measurements are at the top of the table, for that register @200CFM you have a "back pressure" of 0.022 "WC and 600fpm face velocity. You probably have something like https://www.hvacquick.com/products/residential/Grilles-Registers/Grilles/TRUaire-210-Series-Steel-Single-Deflection-Adjustable-Bar-Grilles now, look at the performance info for the 10x6 you have. At 200CFM you have 15' throw (interpolating a bit), 0.026 "WC pressure loss, and 650fpm face velocity. So you would be reducing the pressure by a rather small amount, so you wouldn't get much more air.

Now, if you have an an anemometer to measure wind you could work your way backwards by measuring face velocity. I got a https://www.amazon.com/dp/B01L9SC36A but cheaper will work too. So measure the fpm you have now by holding the anemometer in front of the center of the grille, use the table for the grille you have now to get CFM, then use that to look up the hypothetical new grille to see throw distance and noise level. Note that for ceiling you want curved blades so the air mixes at ceiling level and down't blow straight down on you. You could also go with a round ceiling grille...

If the new grille has lower pressure loss, you will get more CFM, stealing from other outlets. WRT duct, 8" flex doing 200 CFM has a friction loss of 0.024 "WC (http://www.hartandcooley.com/tools/friction-loss-calculator-for-flexible-ducts). Of course I don't know how long your duct is, but it doesn't look like it's going to be a limiting factor, but it may well be in the same range as the grille.

OK, I'm not an expert and an expert would tell you you have to recalculate and rebalance the whole system from scratch if you make a change. And the expert would be right. But you asked how to "wing it, and it doesn't have to be perfect" and I hope that the above gives you a way to make some back-of-the-envelope calculations so you end up in the right ballpark.


Does leaving fridge doors open several minutes at a time lead to partial freezing of food?

You have it correct on how things work.
There is 1 piece missing: the evaporator.
When you open the door, the thermostat detects the temp increase and starts the compressor. The condenser cools the hot compressed refrigerant.
The cool liquid is then metered into the evaporator.
As the liquid expands, heat is removed, and the cycle is repeated.
If you have food touching the wall where the evaporator is it will freeze.
It is not a thermostat problem. It is a problem with things touching the super cooled surface. If there is an air gap between the area that is freezing that air gap will help to cool the box so the compressor will turn off sooner because the air is cooled.
So it is not a thermostat problem as much as an air circulation problem.
My refrigerator has the same issue. It is a side by side. The fridge is on the right. The left side of the fridge is where my evaporator is and if anything is pushed tight to the left wall it will freeze because the surface is well below freezing and the temp in the refrigerator box is still warm. Move the stuff away it quits freezing and works properly.
Since I do hvac work I used a thermal imager and photographed the evaporator so my wife would know the zone to keep open and we have not had frozen things in the fridge with half a dozen grandchildren raiding it.


How much power do I need to soft solder small piping?

The tool you are looking at is a soldering iron.( not a torch ) Most are powered by electricity but some, like the one you mention, are powered by butane gas.

For sweating copper pipes that tool will not be sufficient or provide enough heat. ( it will melt the solder but it will not heat the pipe up enough to make a bond with the solder. )

You need a Mapp gas torch

There are Flame-less options, i have never used one.

Here is brief synopsis of soldering. Family handyman.

And a YouTube video.


Building a barrel stove with a horizontal stove pipe

At my last home one of the fireplace stove inserts had at least a dozen horizontal pipes that also had rock wool on top to baffle the heat going up, the hot air was injected low in the fire box to increase the efficiency it kind of sucked getting it started because of the baffle. Once it started the heat took all the smoke up and out. the baffle was part of what made the stove meet Oregon’s efficiency standards so it can work and although tough to start it may work better for your plan on heating rocks stacked around the back of the drum.


Is it acceptable, or to code, to splice electrical wire outside of a junction box behind drywall?

It is generally not acceptable to have wire junctions be inaccessible.  The rule of thumb is:  All junctions must be in a box, but that box must be accessible - you cannot legally close a box up behind drywall.

There are some limited exceptions, as noted here.

You should run a new line if you don't have the slack.


What could cause the water from melting snow off a roof to be yellow?

There are lots of things that can cause yellow, discounting flying dogs and squirrel infestations.

Are there a lot of trees around?  Leaves may have collected in your eaves trough, or in other places on your roof, and seeped in enough water to cause discoloration.  It could also be something else on the roof - as Eric mentioned, soot is a possibility, though I don't think that would be yellow.  Are there any mines, paper mills, power plants or other sources of airborne contaminants nearby?


Can I install recessed lighting in vaulted ceiling with 6" rafters?

You can install a shallow 6" can made for 2x6 construction.  Halo H27ICAT is the 6" you can use.  Lots of manufacturers make these shallow cans.

You can use regular incandescent, fluorescent and LED lamps and have a large selection of trims.  The only drawback is you can't use taller lamps or they might stick out the bottom.  The most common is the 50PAR30 / 75R30 style lamps.  These are also made in remodel style in case the ceiling is already up.

Here is the spec sheet for the H27

EDIT

I'll give this another try.  I originally deleted this answer because it is not a slope can.  Where I work, some people use regular can lights and use adjustable trims.  Because of the depth you have, 8 inches, this can is 5-1/2 inches.  I suggest you use a gimbal ring trim.  It works like a eyeball, but the lamp is recessed so you don't get that 'bug eye' some people associate with eyeball trims.  You can get the above can in 5 inch or 6 inch round cans, both IC rated, depending on the manufacturer your supplier uses.  Think about a trim like this.

Make sure you use the same manufacturer as the can and trim to cover yourself.  This gives you 2-1/2 inches for your channel and insulation.  If this doesn't float your boat try going to a local lighting showroom and look at what they might have.  If you want recessed you will find what you want. Consider LEDs to keep from getting the ladder out if your slope gives you a tall ceiling.  While considerably more, doing it all together will be less painful.  Either way PAR30 Halogen or PAR30 LEDs offer different beam spreads, so you can at least do something with the lighting.The biggest problem is you can't shine the light back to the wall, mostly straight down or with the angle the can is hung, not backwards.  If you choose this, don't forget the dimmers!


What is the advantage of a double pole switch over a single pole switch?

On-off vs isolation switching

In the UK, a single-pole switch is usually used to turn on and off a light or an appliance. A double-pole switch is used where you need to isolate a circuit for safety reasons during maintenance of the circuit.

For example, current UK code requires a two-pole isolator for fire-alarm control-boxes and for high-power fixed-wiring (non-plugged) appliances such as isolation switches next to electric cookers and electric showers.

The issue is that, in case of a fault being investigated, the fault may have caused neutral to be broken or otherwise to be carrying a voltage significantly different from ground (earth).


Can I remove carpeting that covers a wooden floor?

Sure, just pull up the carpet. At that point, it depends on the condition of the wood floor. If it was in very poor condition and carpeting was installed to cover it up, you may have a big job of refinishing or replacing it. Otherwise, if the wood floor is in good condition, it's mostly a matter of using some color-matched wood putty to patch the holes made by the carpet tack strips' fasteners around the perimeter of the carpeted rooms.


Garage has switched outlets only, cannot operate new garage doors. What are my options?

One option, would be to install a new electrical circuit in the panel, and run it up to the ceiling in surface mounted conduit.


Unfortunately, some questions are not for the innerwebs.  This is one of them.

Find your local LICENSED chimney sweeper. He needs to check your chimney, make sure that not only is the chimney ready for fire, but that all additional openings that may be hidden are properly sealed off.


Do I need steel beams (rebar) for a very short block wall (on top of

Yes, you should add rebar across the joint between to old and new block wall.   Do this by using a masonry drill (preferably a hammer drill) and drill 3-6" vertically down into the existing block wall top where the hole / rebar dowel  will not be in the way of adding the next row of block.  Best to use 1/2" or #4 rebar for this purpose and use the same size masonry drill bit to do your drilling.  It's best to get the block cut and placed into position before you do the drilling to be sure there's no placement conflict between the intended new block layer and the rebar dowel holes to be drilled.  Once you have them laid out on the wall then you can mark the hole's placement. I'd use a dowel in each corner hole and at least every other hole in the new block's run.  Cut your rebar dowel length the depth of the drilled hole plus the block layer height minus 1-2" so they don't stick out of the new walls top.  Fully insert the dowel into the drilled hole by hammering the rebar into the hole with a 2-3# mallet until they hit then end of the drilled hole.

*Rebar is meant to provide stability for the rigid concrete matrix or material.  The reason you see rebar in bridges is that while the concrete provides a platform to drive on it's very rigid and will break apart if stressed past it's physical abilities.  The rebar in the bridge keeps the concrete or matrix or material together and aligned in case of cracks in the concrete and strengthens the overall concrete structure with much less steel than in a conventional steel only bridge structure.


Will I have issues in summer with 120v outlets sharing a double pole breaker with my 240v a/c outlet?

It's fine; see what Ed says.  What Ed is saying is that a circuit serving 120V loads on both legs and also 240V loads is perfectly fine, as long as the circuit breaker has "common trip".  That's so if 120V loads trip one leg of the breaker, the whole circuit gets knocked out - if you left the other leg energized, power would leak into the tripped leg via the 240V loads).
You need to look at how much energy the TV, internet and sound bar take. Most people have no earthly idea how much energy devices take, so just read their labels/nameplates.  If necessary, skill up on what amps, watts and VA are.
And after that, take a hard look at those air conditioners.  Nowadays air conditioners are so efficient that they don't need 240V anymore.  So I would take a hard look at the SEER numbers of your existing A/C vs new ones, and work out the energy costs of each.  Hopefully you are not buying yourself new air conditioners every year, but giving the money to the power company instead of the appliance store.


What should I do if wire gauge is too large to fit into a screw terminal?

If you are using #10 stranded under a screw using a crimp terminal will be the easiest and safest connection.

For that size and application you'd want to use a yellow fork terminal.

Here is a good tutorial: https://learn.sparkfun.com/tutorials/working-with-wire/how-to-crimp-an-electrical-connector


How to connect old wiring to new light switch?

That is a single pole switch.

You should replace it with the same thing and just put one of the wires on each of the new switch's terminals.

Good luck and stay safe!


Identify screw and dowel on this cabinet door

It's not supposed to unscrew.
Loose means you can push the whole plastic plug into the hole.
Fixed makes the plastic plug expand to grip.
This functionality depends on having exactly the right size hole.


Keep losing power and after some time it comes back on?

I would unplug anything plugged in to the receptacles that are loosing power. Call your power company and tell them what is going on. You maybe loosing a phase of power at the panel and or the meter. You all so need to call a local electrical company and have them check the panel.


What accessories, aside from faucets, fit into sink faucet holes?

The most common I've seen.

Sprayer.
Soap/lotion dispenser.
Filtered water faucet.
A Plug to fill the unused hole.

Most single hole faucets come with an extra base piece that covers up the old unused holes.


What kind of screw is this and how do I open it?

Red herring, those are not screws at all. They are rivets.  Rivets are permanent fasteners never meant to be undone, and are used in cases where welding would also be appropriate.  You wouldn't chisel off a weld, so don't chisel off a rivet.

Look elsewhere for the sanctioned/intended way to open up the case.


Unfinished basement is open to vented crawlspace, what should we do to finish?

If the furnace is not one with an open flame, I would seal up / insulate the hole around the air duct that goes to the crawlspace side, then finish off the basement side as desired.

If the furnace has a flame, I'm not sure what you will need for combustible air and safety reasons.  You definitely need a carbon monoxide detector on the basement side if there is combustion.


How can I secure an outwardly opening front door?

You have three points of attack to deal with

The first, and obvious, point of attack for any door is the lock, and to this end, get something good from a serious locksmith.  Abloy's disc-detainers are the gold standard, but anything from a well regarded brand (note, standard Kwikset locks are not well-regarded in the physical security world, and nor is Master Lock!) with decent pinning (six pins, including security pins and keys that don't look as flat as Kansas) and good anti-drill features (carbide pins or plates) should be secure enough for a residential application.

The second point of attack for an outswing door are the hinges -- if you use ordinary hinges on an outswing door, then your hinge pins are wide open to get pulled.  While there are hinges with setscrews or hook-like studs that attempt to prevent an attacker from removing the door by pulling the hinge pins out and then simply pulling the door out, the ultimate solution to this problem is to replace the hinges with fast-riveted hinges that simply won't come apart unless you take an angle grinder to them.  This does mean that you won't be able to "take the door off its hinges" to replace it, though -- you'll need to unfasten the hinges from the door or frame in order to replace the door, instead.

The third and final point of attack is the use of a prybar to try to force the door open.  This can be mitigated through the use of a latch plate cover, as well as making sure the strike anchors securely into the frame.


Can we install an above-counter sink (large, about 31" x 18" x5") on a bottom-mount countertop?

This will only work if the new sink (including the lip that sits on the counter) is larger than the old sink - it looks like your new sink is actually a bit smaller (13x18 vs 16x19.5) which means there will not be any surface area on the counter for it to rest on.

Lets say for a second you did find a slightly larger sink.  You now need to consider the counter material.  If it is a laminate counter you can easily enlarge the hole for the new sink, however if it is a stone like granite, you will need some specialized tools and know-how in order to enlarge the hole; it could end up being cheaper to just replace it.

You also need to consider how you will remove the old sink.  If the new one is a fair bit larger you can just cut it out, but if margins are tight, you will need to very carefully break the old sink free without damaging the counter.


My GFCI/AFCI 20a kitchen socket warning lights are both flashing

Stop throwing parts at it and actually troubleshoot
It would help to read through your GFCI/AFCI instructions and get clear on whether the device is indicating GFCI or AFCI fault.  In other words, treat the indication as if it is genuine, and not just gibberish from broken junk.
Let’s ditch the red herring: it ain’t the MWBC
We know it’s not the MWBC (Multi-Wire Branch Circuit).  First, there is nothing wrong with MWBCs in general, but they do require special handling for GFCI and AFCI.  The idea of an MWBC is to share a neutral, and that is incompatible with two 120V sub-circuits each having independent GFCI devices.  The neutrals in each GFCI’s protected zone must be kept separate from any other; and travel only with the protected partner hot.
It’s no problem to do this with MWBC wiring; the two sub-circuits simply must diverge and never share a neutral after the GFCI(s).
We know your kitchen is wired correctly because if it was wired wrong, it would instantly trip with ANY use on the shared GFCI downline, and that is not the symptom.  Also it was wired by a pro, who would know better.
So it’s not an MWBC problem.  MWBC is simply something you must be aware of while working on the circuit.
Whenever a GFCI trips, immediately check appliances
The first thing you must do is unplug everything on the downline of that GFCI.  See if the problem clears.
Meanwhile, take those appliances to a distant unrelated GFCI and see if they trip it there.  In this case you’ll also have to test for AFCI trip, so try it on an AFCI also.
Next, check the downline
Remember, we’ve already pulled all the appliances on the downline, so that’s not it.  It must be in the wiring.
If that does not clear the problem, we pull the GFCI out and remove the wires on the LOAD terminals.
If you can’t abide losing power to that downline, temporarily move it to LINE.  However make sure to put it back!
With LOAD terminals empty, and nothing plugged into the GFCI, it must hold and not trip.  If it trips, the GFCI is defective (not likely).
Since the GFCI did not trip, we are back to troubleshooting the downline wiring.  Follow it, then divide, and conquer.  Reconnect it to LOAD, split what remains of the circuit and see “which side” the problem is on.  Rinse wash repeat until you found it.
AFCI trouble
Since these GFCIs are also AFCI (what’s the point of that?) the AFCI will detect wiring faults in the downline, or even in the supply/upline to some point.   The usual suspect is “back stab” connections at receps: convert those to side screws.  Make sure the side screws are all “run down” (not sticking out, they come stuck out by default, and backstabbers ignore them because backstabbing is all about being in a hurry)... and aren’t hitting a metal box or a ground wire, e.g. as a plug is wrestled in/out.
Since AFCIs literally “listen” to the wire for the crinkle-crunch sound of electric arcing, it’s possible for them to hear that on the upline.  So an AFCI trip might result in wiring problems on the LINE side of the AFCI, back to the breaker and neutral bar connections, or even a loud arc fault on another circuit!
AFCIs are not required in kitchens, and if they were, AFCI receptacles are an unacceptable shortcut unless the wiring to the panel is in metal conduit.   So in all seriousness, getting rid of the AFCI function is an option.


Should my roofer have vented my insulated roof?

You are absolutely right. The kind of roof you describe does not need to be vented, and in fact cannot be vented without compromising all the polyiso insulation you had added (that was a good idea!). The roofers have damaged your insulation layer and put your roof at risk. Call them back and make them fix it. If they won't, call the contracting board.


What does the 10 flash signal indicate on my garage door opener?

According to this site, 10 flashes means the door sensors have detected an obstacle.

  When properly connected and aligned, the sensor will detect an obstacle in the path of its electronic beam. If an obstruction breaks the light beam while the door is closing, the door will stop and reverse to full open position, and the opener lights will flash 10 times

Depending on the make and model of your opener, this may be what's causing your problem.

Depending on the sensors, there might be lights on the sensors. Check the manufacturer's documentation to determine what the color and/or status of the lights should be.


Why does my kitchen faucet suddenly have too much water pressure?

Here are three different options:

Installing a more restrictive aerator on the faucet.
Installing ball valves on the incoming water lines.
Installing a water pressure regulator.

Since you said it hasn't always been like this, and it seems as though the faucet is the only thing you're having problems with, I would go with an aerator first.  The old one has perhaps fallen out.


Unable to turn off cold water flow in airconditioner, possibly due to solenoid valve

That's not an air conditioner at all.  It's nothing but a radiator in a fancy dress.

The unit is designed to be supplied chilled water at 6-12°C (43-54°F) and blow it across a - well, a radiator.  It has a tray to catch condensation.  And that's about all there is to the unit.

So it's totally dependent on external machinery supply chilled water to it, and this machinery is fairly complex. Which tells me you are in a multi-unit apartment/condo building with maintenance staff who tend to that equipment. Since this equipment is only the "head unit" for that system, and you don't control that system, you need to talk to the superintendent. They fix these things all the time and probably have spares in stock, which is good since you'd have trouble finding these at retail.


Consider an Air Admittance Valve, rather than a traditional vent, in this situation.  The downside is these are mechanical devices that in theory can fail.  The upside is reduced sewer venting to the atmosphere and less pipe.

Buy a quality one: there are $3 models that are not the same thing.  Look for a series of certifications for this task and expect to spend at least $30.

A vent that goes up and then down is not OK.  AAV's are approved in the International Plumbing Code, and the USA National Plumbing Code.


Can I use three 2x8 beams instead of two 2x10s for a deck?

Reference the American Wood Council's Residential Wood Deck Construction Guide free download pdf.

It looks like 3 2x8 beams allow a longer joist span than 2 2x10s.


Do I need to insulate both hoses on a portable AC?

No.

You insulate the exhaust hot hose because you want exhaust air to stay hot until it is outside.  If heat radiates off the hose while still inside, that heats the house back up and partly negates the work your AC just did.

Usually you don't really care if your intake air gets a little cooler on the way in to the AC.  The only reason I can think of to insulate the intake hose is if your intake air (from outdoors) is also considerably hotter than your conditioned inside air, and you risk heating the inside just with your intake air.  I suppose if you are in a very hot climate and you are getting things really cool inside that might be the case.


How to skim coat a wall that receive a heavy light at night?

You should take note of Ed Beal's comment above. I am a bricklayer by trade and I have seen this same problem with wall mounted lights on brickwork a lot. The brickwork looks, no, IS spot on, but at night, it looks steppy because (most) bricks are not flat.

I'll stick my neck out here and say that it's going to be very difficult to get a perfectly flat surface with cement based coatings/ rendering etc. i.e good enough to shine lights down.

The answer is to do what the historic buildings do. Shine the light ON the building (not down it). Not only does this look spectacular, making the house stand out, it will of course totally 'hide' the walls you're not happy with. This usually means lamps mounted in the grounds/bollards etc. and angled back towards the walls.


The ridge vent can allow driving rain in, but for it to be showing water damage, it would have to be getting in during nearly every single rain.  Is this area of the garage perhaps where the driving rain comes in or is there possibly something that cannot be seen in the pictures that would be directing more than normal water in?

I don't think the tar paper is supposed to bridge the ridge like yours is.  I can't seem to find an install guide online at the moment, but last time I installed ridge vent, we did not have tar paper across the opening and the roof has no water.  I wonder if the water is getting on the tar paper and is getting through a nail hole causing this issue.


I would hire a contractor to blow it in from the inside. They drill a hole and fill the area of each bay They also do this in walls. I would never punch a bunch of holes in my roof that is asking for problems especially in your climate.


Installing Neurio home energy monitor, can't get to service wires

Based on Tyson's response I called my power company. They came out, cut the power to the house and removed the meter for me to get access to the top half of the panel. I was then able to complete the Neurio install and it seems to be working fine. Thanks to all who have answered.


What size wire should I use for my yard shed, and how deep should I bury it?

One trench the whole way will be easier to pull cable through.  You could make it direct, one straight line, or closer to it than otherwise.

Fences can get blown over, run into, replaced for service, or removed for aesthetic reasons, which will become more of a pain to deal with if you run conduit along the fence.  Also its less pleasurable to look at conduit than to not.

Your municipality or county should be able to tell you your local minimum depth for buried cable.  It depends on your jurisdiction if you're asking about code as I assume.

I would recommend oversizing the conduit significantly to make pulling easier and allow for easy upgrades in the future.  2" can't be that much more than 1".  It will be more durable and it could save a lot of work later on.

You can save costs on grounding by using bare wire, or using metal conduit as your grounding conductor.  But I would not bury metal conduit to avoid dealing with corrosion.  Even a bare ground conductor inside a plastic conduit is going to fare worse than a sheathed over time.

Paint a white line where you plan to excavate and call your utility locating service out to mark obstacles. The white line or shape will keep them from needing to mark unnecessary things in far off parts of your yard.

Rent a trencher and make the work easy on yourself.

Bury conduit larger than you need, because excavation sucks.

Dig depth is often 2foot minimum for nonmetallic, 6 inch minimum for metallic, but ask your codes department what they will approve.

For wire gaguge, use a calculator like http://wiresizecalculator.net/.

By my estimate you would want 6awg, but maybe the direct patch can cut down distance and let you use smaller.


Are there concerns with leaving part of a home's ground level unfinished?

The full basement may cost 3 times what the corresponding slab size may cost from a concrete perspective. But you have to also consider the cost per square foot to build the structure that covers the slab/basement. If you double your slab size you need twice as large of structure to cover it. On the other hand the structure footprint is the same size whether it has a basement or a slab under it.


Replacing rusted steel post with 6 x 6 x 6 pressure treated lumber

Just wanted to says thanks for the advice.  I was able to replace all the steel post successfully and without too much trouble.  I did build 2' deep piers for each post, 8 inches in diameter.   Each pier took two bags of 50lbs concrete. On these I places a 6x6 post base with bolt secured into the concrete.I use a jack to slightly raise the porch floor so I could remove the existing post and install the new ones.  Taking my time I did each post one at a time.

Final result:


The simple answer is "yes". Every piece of insulation you put in is a bit of heat that's not lost to the outside world. This is better for you as your house is warmer and your fuel bills are lower, it's also better for the environment as you're not using as much energy.

The more complex answer is "it depends". Buying and installing the insulation costs money (you don't say!) so the immediate equation becomes "is this cost less than the money I'll save over X years?". It's the answer to this that will, largely, affect your decision on whether to insulate or not.

The company who wouldn't estimate may be right (for their system) in that it would cost $2,000 (say) to do the work, but you'd only be saving $20 a year on your heating. This would mean it would take 100 years to pay back the cost. Now, if you can find a system that costs less then the proposition becomes more economical. Insulating the ceiling/roof space is a good thing to do anyway.

However, if your primary concern isn't the savings then you might decide to go ahead regardless.


How to stop this small roof from leaking?

I believe that you are getting leaks through that gap. Wind driven ran can push water right under that flashing.

You can install sealant underneath the flashing like Aravindakshan K suggested. I would take it a step further, and add roofing nails with the neoprene washers on them to hold the flashing closer to the roof.

I have the same problem with my front porch. It doesn't have proper footings and has sunk over time causing a separation in the flashing. Your roof appears to have the same situation. It is likely that that separation will continue unless you address the structural issue.


Door replacement - will door still be solid after cutting?

On numerous occasions I have had to cut hollow core doors off more than the available blocking in the top / bottom of the door. What I have done in these instances is to take the cut off bottom piece and then reclaimed the inner block for re-use. If a table saw is available it is quick work to set the fence just right so that a couple of rip direction passes cleanly cuts off the outer laminations. Alternatively the laminations can be removed using a plane.

Once the block is nicely cleaned up it can be glued and slipped right up into the open bottom of the door. Use a couple of 1x4 boards on either side of the door and some good sized C-Clamps to tighten up the glue joint so that the glue can dry without any gaps.

Note that often the inside of hollow core doors has an internal webbing of cardboard material to bridge the gap between the two lamination skins of the door. Sometimes it is necessary to use a chisel inside the cut open bottom of the door to scrape back the glue joint of this web material on the laminated panel. If this is not smoothed out the re-claimed bottom block will make the laminated sides bulge out when trying to glue the block in place.


Sticky Rocker Light Switch -- Not stuck, just sticky -- fix or replace?

That's not the kind of device that you'd attempt to repair. For one thing, you'd void the UL listing and assume liability for any resulting damage, injury, or death in doing so. For another, parts aren't available. For one more, they're far too inexpensive to waste any time on.

Buy a new switch. Turn of the breaker. Replace it in the same configuration following standard good wiring practice. Be happy.


rubber seals in unheated shed over winter have broken down,

The water in the attachments froze over the winter and broke the valve bodies.  thats why they are leaking now.  next year, take them and your hoses inside before freeze up.


How to flatten the sagging OSB subfloor?

A 5/32" depression is not that bad actually. Assuming you don't have a problem with the floor joists that need to be stiffened, you have a couple of options. First, I would span the area with a 8 or 10 foot straight edged board to visualize the areas that are depressed. Much like your pic, I'd pencil out the area on the floor so you can see it clearly. Be sure the existing subfloor is securely nailed or screwed down. Add screws if necessary so there is no bounce.

The easiest method would be to use embossing compound. Mix up a good amount and trowel it on the depressed area. Use your long straight edge to screed it, much like you would a concrete slab.  Since your depression is only a little over 1/8", it should be very easy to spread that small amount. Then using a 12" trowel, just gently smooth it over maintaining the depth of fill. Embossing compound in this application is best as it fills easy, dries quickly and easy to sand if you feel you need to remove any ridges, etc left behind after it dries.

Once you have completed this task, evaluate the overall flatness. If you still have some small dips, use more compound or opt for a layer of 3/16" plywood.  Remember, always use a layer of red rosin paper between wood layers to prevent squeaking.

You may also opt for a higher quality backer for your engineered flooring. There are several different backers available. They range from ultra cheap thin foam to much better thicker, sound deadening composites. If the engineered wood flooring is 3/8" or thicker, the combination of a good backer and the flooring will bridge any very small irregularities still left on the subfloor.  Don't worry about small differences, they will not show.   Good luck.


What's wrong with my painting technique?

Latex paints have a known attribute that allows certain things to persistently come through the paint even though you try applying multiple layers.

I once had a problem of a wall that had a poster glued to it by a previous owner. I removed the poster and apparently the glue residue, however small it was, kept changing the paint I applied over that area.

Another time I was trying to paint a door that had been finished with an oil based product. I had worked diligently to strip and sand off the old finish before painting. Unfortunately the old finish had penetrated the wood to varying degrees in different spots. The paint I applied to the door was not uniform even after four or five coats - hard to remember exactly how many as it was 25 years ago.

The fix for both of these problems is to apply a sealer / primer product  like Kilz before applying the final paint. One needs to make sure the surface is properly prepared before applying the sealer / primer. Light sanding can help and washing with a strong solution of hot water and TSP can help.


Shou sugi ban treatment of external timber cladding

Charcoal (if not burned) is forever, more or less (ask an archeologist if you doubt that.) As such I'd have to doubt that cleaning which does not go so far as to remove the charred surface will help, nor will time and weather do much.

Linseed oil would be a reasonable approach for a building exterior, though I'd certainly test that before proceeding.


In most cases, if you have done all the right things like sanding and cleaning between coats, you should be done and have an excellent smooth glossy finish. Any further sanding or polishing with any kind of abrasive will dull the finish. Normally urethane does not need a wax. After some use and a good week or two of total cure time, a regular furniture wax like Pledge or Butcher's Wax will help keep the finish clean and shiny. Never use an abrasive polish. If the finish dulls over time, buff it with 220 grit paper and give it a fresh coat of urethane. This should not be required for a long time depending on usage.


What's the right way to insulate and frame around this pipe?

Skip option number 3, you don't want to have two half walls with a framed in gap between. It's not stable so you'll have cracking and likely other issues.

Option 1 implies that you need to fill all the open space with insulation, that's not the case. You need insulation between the outside and inside, but once you have enough insulation installed (for your desired R value) and a continuous envelope around the home, there's no need to keep adding more to fill a void.

So your options are either 2 or one unlisted option. Your option 4 is to insulate against the exterior wall and behind/around the pipe as best you can, and then install your wall in front of the pipe. The main difference between option 2 and option 4 is whether you insulation directly against the concrete wall or inside your framed wall. Inside the framed wall will be easier and likely use less insulation material. Against the concrete wall will allow you to more easily fish wiring inside the framed wall.


Should my receptacle tester be able to trip a GFCI breaker in the panel box?

If the receptacle is grounded: Yes it should trip it.
If the receptacle has some semi-grounding that is insufficient to clear a dead-short bolted fault (i.e. incapable of flowing 200A without setting the house on fire): Yes it should trip it.  And that is fine. A bolted fault is also a ground fault, which should trip the GFCI, ending the event.
If the receptacle is not grounded: No, it should not trip it. That would be disturbing if it did.
If the receptacle is not grounded, but a tester indicates grounded: Then a) no, it should not trip it, and b) that is a bootleg ground that defeats the entire purpose of even having a GFCI /facepalm /Darwin_Award and needs to be corrected ASAP.
If you stick the GFCI tester in a 2-prong cheater and come off the ground tab with a separate wire run across the house to a part of the electrical grounding system: then yes, it should trip it.


Does it make sense to build a false wall at the back of a shower bay and what do I need to concern myself with if doing this?

Absolutely, why not? A simple stud wall would do. Just make sure that the wall is going to stand up to any possible water ingress by using concrete tile backer rather than any kind of plasterboard, taping the joints and sealing everything. To me, it seems like common sense to build your enclosure around the complexities of waste water pipe routing.

EDIT: I think what you refer to as drywall is what I refer to as plasterboard. Either way, you don't want it in a shower, unless you're doing to tank it.


Is torn kraft paper vapor retarder in the attic a problem?

The purpose of a vapor barrier is to prevent moisture from condensing in the insulation, greatly reducing it's insulating value. To do this, it must be placed on the warm side of the insulation. In cold and moderate climates, this is towards the living space. In hot humid climates where keeping the living area cool is the primary concern, it goes towards the weayther side.

It sounds like in your case the paper is on the top, weather side. If you are in a hot humid climate and you are adding more insulation on top, you WANT to have many holes in the old barrier that is now sandwiched inside all the insulation, allowing any moisture that got past the new barrier on top to hopefully get carried out without condensing.

If you are in a cold or moderate climate, and it is on top, it was installed wrong. You're better off having holes in it. Any moisture that got that far should be allowed to escape, lest it condense on the paper and make the insulation wet.

To summarize, in either climate, if the paper is on top of the old, and you are adding more insulation, put all the holes in it you can! It is not helping. In a hot humid climate, insure you place a new barrier on top of your new insulation. If you are in a cold or moderate climate, consider how you may add a vapor barrier to the living space. Several heavy coats of latex paint can do this. It may be something you already have.


What quick and dirty tool/method should I use for cutting scrap drywall?

A craft knife or box cutter will do the job very quickly and cheaply.  You only need to score the front side of the drywall and then it should snap cleanly enough along the score line.

If you already have a Dremel or Roto-Zip, you can get drywall bits for them that will make short work of any drywall.


Need an apparently-discontinued moulding profile; where to look?

take a look at this suggestion from ask this old house:

  When none of the offerings at the home
  center or the lumberyards measure up,
  then it's time to go the custom route.
  A millwork shop can make special
  "knives" and turn out an exact
  duplicate of your existing moldings.
  The problem is, you have to pay setup
  fees, which increase the linear-foot
  price significantly and may not be
  cost-effective for a small order like
  yours.

  The way to avoid those charges is to
  make your own profiles using a table
  saw, band saw, and router. On the next
  page, you can see all the steps I
  follow in order to copy a short piece
  of baseboard cap. The process isn't
  difficult, as long as you're familiar
  with and respectful of these powerful
  tools.


I want to be able to time my in wall air conditioner. Can I update the controller?

How I hacked my window unit for IOT control:

This (admittedly slightly janky) setup allows me to easily undo the modification in case I need warranty service or I'm going to resell it. I didn't have to use a soldering iron or spend all weekend trying to hack into the control board; I just hijacked the code the AC already runs by lying to the program's inputs.

My window AC had a thick solid copper "wire" centrally behind the intake filter that connected to the thermostat. It's usually placed there so as to sense the temp of the incoming room air more than the outgoing cold air. If that sensor gets hot enough, the AC turns on. This is typical and common. You might have to remove the plastic face of the unit to get to the probe, but you don't have to deeply disassemble the whole thing.

I first cranked the AC thermostat up to 85F, making so that it almost never comes on, unless it gets really hot in the room.

I then taped a small heater to the AC's exposed copper temp probe. you can use a strip from electric socks, a USB drink warmer, or if handy with electronics, use a simple ~150 ohm resistor to short a 5v power supply. You don't need/want more than 1/4 watt of heat.

Wrap the heater and probe tightly with gorilla tape. You should be able to smush it all in-place and keep the cover as expected. The thermostat is almost useless at this point, so it doesn't even need to stay in the air flow, you can tuck it all to the side if needed for the fit.

You might tell where this is going.

To turn on the AC, my smart home system applies 5v to the heater from an arduino-like box. This raises the temp on the sensor above 85 and turns on the compressor.

My smart home uses an external temp sensor to monitor the temp and tell probe heater when to turn on and off. The AC on/off state will be the opposite of the small heater on/off state.

This mod isn't for everyone, but it's probably more approachable for many than splicing into the AC's wiring or trying to clone an IR remote control.


Can I terminate my dryer vent next to my gas meter?

An opening under the building code would typically be a door or a window.
If you have a gas leak, the dryer vent nearby doesn't significantly increase the hazard of the gas leak, because the hazard of a gas leak is massive.

On the other hand, blowing hot moist air on a piece of equipment is more likely to create maintenance issues and routing a new installation is typically pretty easy, it's probably worth a little extra trouble to avoid venting directly onto the meter.


Removing or leveling an old iron pipe embedded in concrete patio

Option 1(clean finish):Rough cut the iron, bar the concrete, and pour a top layer of grout or thicker layer of concrete.

Option 2 (rough finish, what you're doing): Rough cut with rip saw and finish with grinder.

Option 3 (rough finish, completely removes visible pipe): Clear adequate space around the pipe below the concrete for a cast iron pipe cutter

You're going about it the right way.

Option 2 details: Depending on your comfort with a rip saw, you may want to start with a masonry grinding wheel to smooth ~4" of the concrete around the iron to minimize risk of kicking against exposed stones (aggregate).

Using a medium gauge cutting blade(https://www.lowes.ca/reciprocating-saw-blades/lenox-es-2017-14-tpi-lazerreg-metal-cutting-reciprocating-saw-blade-5-pack_g2347551.html?searchTerm=lenox-lazer) trim off all that you can comfortably trim, follow up with a cut off wheel (https://www.amazon.com/Walter-ZIP-Cutoff-Wheel-Pack/dp/B00NFHM9E0)

From the 18" that you mentioned, this should take around an hour with out breaks. You'll need roughly two discs and two blades.

Option 1 is significantly more expensive and time consuming.

-Start by deciding whether you'll use grout (minimizes the profile[depth]) or concrete, if you're using grout there are specifics that need to be considered, if you're using concrete, it's straight forward, minimum 2" pour.

-After you've decided which (or any other local option) you're going to use, use a rip saw, (or as another has suggested, a torch) to clear the pipe from the surface, leaving it partially exposed doesn't matter, as long as you can have it completely enveloped by the concrete.

-Depending on the state of the slab, and your weather, you'll want rebar spaced at around 16" square from each other, figure out how much you'll need based off what you're expecting to add (min 4"), purchase re-bar and structural epoxy or grout.

-Mark off and drill the holes based off of what you're inset is (min 3") again at 16" square (more or less based off your weather)

-Pressure wash the surface, and clean out the holes from all dust, and sitting water

-Set the re-bar in to the holes with the grout or structural epoxy while waiting for the compound to cure/set...

-Frame off the slab for the pouring of the concrete and making sure it's moist but no sitting water (if it's grout, there can be sitting water for concrete) and finally perform your pour.

There isn't any more guidance that I can provide for this option, it can vary wildly based on what your local weather, building materials, expectations of quality, and more.

Option 3 can vary depending on the thickness of the slab, it can be time consuming, and requires renting of any tools you don't already have (SDS, SDS bits, cast iron pipe cutter). Again I can edit and provide more details.


Loose plug in outlet makes circuit work - Weird Issue

I suspect the receptacle is the problem.  Either one of the screws are loose or it is the old stab-in back wired receptacle which were notorious for problems.  The new stab-in's are much improved.  Either way I say replace the receptacle. They need to be changed periodically any way.


Second Pressure releif valve in hot water system?

I have not heard of a TPR valve being required outside or further away from the water heater there would be less of a chance of valve opening for temperature the further away it was from the heater. I have seen reliefs on hydronic systems at a lower pressure to protect the embedded plumbing but not water heaters. Possibly a work around for a drain that the one at the water heater did not have.


As we always advise, the secret to a good paint job is proper preparation. It can be a pain, but you must remove all loose and peeling paint, wash the surface and Spackle holes and cracks before priming and painting. Often a light sanding is a good idea, especially on any glossy finishes. Be aware of lead hazards on any paint applied before 1978.  The actual application of paint is the easy part, don't rush the prep, it is the most important part.


Downsides to staple up radiant heat, besides cost?

Here are some potential downsides, besides cost (which is a big one):

Can't have central air conditioning.
How to heat the basement? I assume you plan on insulating under the PEX tubing to make most of the heat go through the floor. This makes it tough to heat the basement, if that's something you want.
Will the warm floors be noticable? For well-insulated and relatively airtight homes, the floors generally won't get warm enough to notice any improved comfort, on most days.
Slow response to weather changes - Plate-and-tube less so than in-slab tubes, but this system type can be slow to respond to fast weather changes (see p33-39 in http://www.duluthenergydesign.com/Content/Documents/GeneralInfo/PresentationMaterials/2013/Day1/hydronics-siegenthaler.pdf)
"Furnaces dry out the air" is a myth.  You didn't specifically mention this, but it is a commonly held belief that forced air heat dries out the air more than radiant heat. This is a myth. See: bookstore.ashrae.biz/journal/download.php?file=ASHRAE-D-AJ11MarHVAC-20110305.pdf


Floorplan reasonability check: would need to put a kitchen drainpipe in a concrete subfloor slub

You could install a laundry type pump system to pump the kitchen water overhead . I had one of these pump systems in a laundry area in an apartment I lived in and it worked perfectly. And, if you wanted to add a bath room or powder room they have systems that "pump up"for that too.


Identifying and sharpening carbide tipped planer blade

The blades certainly have some sort of inset visible at the edge, which might well be carbide.

Home sharpening of carbide is possible with diamond abrasives.

But, if you have to ask, it's likely that a better job will be done by a competent shop, since you inquire about "best."


Is 16x20 feet big enough for a 2 car garage?

The ideal size will vary with the size of the vehicles you drive. There is a vast difference in the space required to comfortably open the doors and exit a Mini Cooper and a full size pick-up. I live in an older home with a 2 car garage built in the 1920's. The inside dimensions are 18' by 18'. To fit 2 cars (06 and 08 Chevrolet Impala) in it, the one on the left must be backed in and the one on the right driven in. Exiting the vehicle requires caution to keep the doors from dinging each other. Opening the passenger doors is impossible as there is less than a foot of clearance to the wall. Doing any kind of repair or maintenance in the garage is impossible with both cars inside.


It's likely that your floor is tongue and groove. That is, each piece of flooring has a tongue that sticks out on one side and a groove on the other side that the next piece's tongue sticks into. This is very simple for the initial installation, but it's impossible to install for a repair without some accommodations. The good news is that the accommodations are easy to make.
I'd suggest that a longer piece will be easier to install than this little short piece with the added bonus that it will look less like a patch, thus looking more like a just a short piece of flooring and, therefore, more "natural" in the floor and less like "here be a patch stare at it in annoyance".
To install your repair:

Chisel out the old repair. As short as this patch is, I don't think there's going to be any easy way of cutting this out with any sort of power tools. If you decide to lengthen the patch, you may be able to make a plunge cut with a circular saw to cut down the middle of the board, then pry out each side. It's highly unlikely that there would be any nails in the face, but if you cut too deeply into the subfloor, you could hit a nail with the saw blade, so take care. If you have a plunge router, you could use a straight cutting bit (an up-cut spiral bit would make easier work of this, actually) to slowly work your way through the depth of the flooring piece, but the caution about hitting a nail in the subfloor goes up even higher. You do not want to hit a nail with a router bit spinning at 25000 RPM. That's NOT GOOD™. Use all the standard precautions for using a router, of course, just apply extra care.
Get the remaining edges of existing flooring as square as possible so it looks like it was meant to be that way. An oscillating flush-cutter may be your best bet for getting the edges squared up if you're not handy with a chisel, but a nice, sharp chisel should cut your wood just fine. If it's a manufactured floor (not solid wood) the power tool will probably work better than a chisel.
Cut out your patch from a piece your spare flooring to match the length of the new hole (either existing size or lengthened).
Cut your patch piece to be a snug (lengthwise) fit into the opening you've just created. A very slight bevel (1-2°) with the back of the board smaller than the face surface could help making installation easier, but I would make it a very slight bevel.
On the back side of the patch piece, cut off the bottom portion of the groove. You want to cut only the back side of the groove, don't cut into the top side of the groove, you'll weaken the top surface. This could, potentially, allow the top of the groove to break off in the future, necessitating another repair.
Put adhesive into the exposed groove on one edge of the existing flooring and on top of the exposed tongue on the other side. You do not want any glue between the floor and the new piece. You can use standard, yellow, PVC carpenter's glue, or you could use something stronger like a construction adhesive. Standard yellow glue is more than strong enough, is cheaper, and it's easier to store an opened bottle than it is to store an opened tube of construction adhesive. I would not recommend epoxy - it's not necessary and they tend to set up too quickly. If you choose to go with epoxy, get one with at least a 10 minute working time - the longer the better. The next step could take a minute or two.
To install, push the patch piece, tongue first, into the groove of the existing flooring. You may need to use a block of wood against the groove side of the patch and bang it into the tongue with a rubber mallet. Use caution - if you bang at too much of an angle against the top of the groove, you could split it off, especially if this is a solid wood floor (it could split along the grain in this thin area). If it's a particle board based manufactured floor, the particle board is very likely to fracture along the thin edge of the groove. Your best bet might be to use an additional scrap of flooring with the tongue of your "banger board" inserted into what's left of the groove of your patch - this will distribute the blows across the grove and into the main portion of the piece, and will help align the blows across the face of the patch instead of at an angle to it. A plywood based manufactured board may have plys running across the groove, it may not - take a look at your flooring to see. Use appropriate caution with plywood, too.
Once the tongue is seated as far in as you can get it by driving it sideways, place your scrap block of wood on top of the patch and hammer the groove side down with your mallet. Ensure your new piece of wood is flush with the surface all the way around. Anything sticking up will be a trip hazard until it's sanded flat, and that will require refinishing (and a whole new question).
Wipe up any glue that squeezes out. You can use a damp rag, especially if the wood is already finished - the finish should do a fine job of protecting the wood from a few moments of damp. A tip I've recently picked up is to rub the glue up with some sawdust - this fills gaps with the sawdust and does not involve getting the wood wet, which can raise the grain. The drawback, in this instance, is that you really don't want a filled gap of sawdust visible as it will look noticeably different than the finished floor and the gaps between the other boards. If you have a narrow blunt object, like a putty knife, this could work if you wipe up most of the squeeze out with the sawdust, then clean out the joints with the putty knife. NOTE: I've no experience in this, so I don't know how well it may work.
Dry off the surface from any excess clean-up water. A quick rub-down with some paper towel should be sufficient.
Cover the patch with a sheet of waxed paper. This will help prevent any remaining glue from sticking to the board you're going to use in the next step.
Lay another piece of wood on top of the new patch and pile some heavy weight on top of the scrap wood. This will be your "clamp" to hold the patch down until the glue sets.
Let it cure for the amount of time recommended on the package. Be sure to allow additional time if your floor happens to be closer to the cold end of the working range of the glue. There's nothing wrong with letting it sit until the full cure time has elapsed, other than the minor inconvenience of walking around a pile of stuff on the floor.
Stand back and admire your handiwork!

Just be sure to take your time at every step of the way to ensure that you're not damaging any of the flooring that will remain behind or doing any damage to your patch piece as your installing it. Do more than one test fit if necessary to ensure the patch will fit in - ensure that tongue side fits in (lengthwise) next to the groove of the existing floor and make sure the groove side of the patch fits lengthwise next to the tongue side of the existing floor. Unfortunately, this is not a place where you can do a full test fit, as once it's in place, it will be very difficult to get back out without damaging it, so you'll have to go with "that feels about right".