Is it OK if I can feel fiberglass cloth texture after curing?

Perfectly normal, and unless you have some need for it to be smooth, not a problem. Many less-fancy fiberglass products have the fabric texture exposed.

The bigger concern for longevity is then covering that material (which is highly subject to sun damage) with an adequate layer of paint to protect it from the sun.

Since you mention that you are preparing for paint, sounds like you'll have that covered.


How do I even out a pair of bookcases on an uneven floor?

Attaching the bottom of both bookcases to a single flat board will get them aligned right.
Then you'll just have to shim once to get things properly vertical.  If the problem is extreme, consider bolts or a backboard to connect the sides of the units.
Both these options will improve overall stability of the pair.
Depending on the aesthetic situation, you could use anything from 3/4" BB grade plywood to birdseye maple for the boards.


How can I wire this replacement bathroom extractor fan?

If indeed the old assembly was a low voltage fan there is likely to be a transformer located nearby that stepped the AC line voltage down to the low voltage required by the fan.

On the other hand the fan that you mentioned as the replacement appears to be one powered from a 220-240V AC 50Hz power line source. The data sheet I found was here.

It would not work to connect the new line powered fan to low voltage wiring. So if your old fan was indeed a low voltage unit you have some significant re-wiring to do.

The three wires that you describe for the new fan need to be wired to a switched power line for the manual turn on/off. The neutral connection is clearly the return path for the current from the fan. The third wire which is the "always powered" should be connected to the same AC source that is in front of the switch for the switched circuit. This always on power connection implies that your new fan has some additional capability such as a humidity sensor circuit that can run the fan when the bathroom humidity is high even when the normal switched circuit is turned off. (Note that locating the humidity sensor needs to be done with care. If there is too much air flow from the fan being drawn across the sensor it may not register the humidity level correctly).

As with any product installation you really need to carefully follow any instructions on the data sheet included with the new fan from the manufacturer. Use the information given here as a general guidance but make sure you understand specifically what you have in hand and the existing situation. If you are still unsure of the details then it may be best to call in a professional electrician.


Is it useful to paint outdoor conduit white to reduce the temperature?

Elevating the conduit 7/8” or more off the roof surface will be more effective than painting but yes white is the least heat absorbing color.  Why 7/8” elevation? That is what code requires or a temperature adder is used when derating the wire; with 7/8” elevation, the adder is not required. This is located in section 310.15(A)(3)(c), "Raceways and Cables Exposed to Sunlight on Rooftops".


Do I need to hire an electrician to turn off my main?

To close the loop: I contacted the electrician who did the installation. The lower lock tag can be removed.


Is it okay for an electrical switch to get warm?

Short answer, most dimmers do get warm when in use. If the dimmer does not have a mechanical method of turning completely off. Then there is a good chance that you are still getting some electrical flow through the switch and that would mean the dimmer could stay warm. In other words what @Harper said.

The biggest question I would have would be if it was getting excessively hot? I would say somewhere above 30 C (86 F) would seem to be excessive.


Most AC units say specifically NOT to use extension cords.  The reason for overheating is voltage drop caused by the possible smaller gauge of wire and length of the extension cord.  An appliance rated at 12amps probably has a 14 or 12 gauge cord. If your extension is a smaller gauge, it may be too small for the current and heating up like an old fashion fuse.


Install a ceiling light - confused on the ceiling wires color

What you have there is metal conduit.  You can tell because it's modern construction but no ground wires.  The metal pipe is the conduit.
It's common with conduit for other, unrelated wires to "pass through" your box.  There's nothing you can do about that except understand not every wire up there is related to your project.
Deciphering the wire colors
The problem is, in North American wiring, color codes are a bizarre mess - however in conduit work, the color codes clean up a little bit.

Safety ground is Green, yellow-green, bare or metal conduit
Neutral (the normal current return path) is white or gray
Hot is every other color, with no standards for always-hot vs switched-hot vs travelers etc.
And that is the end of the color coding.

But we have 1 of the 2 wires that we need: Neutral.  In conduit, white is definitely neutral, so you know you add the lamp's white wire to the existing bundle of whites.
The other wire is a mystery.  I suspect the red wires are simply passing through, and have nothing to do with this lamp.  Let's disregard those.
That leaves orange and blue... either of which could be your active lamp "switched-hot".   Honestly, given that we're hooking up a lamp like this and we know neutral, you can't do too much damage just trying one. That's what I'd do.
Have the circuit breaker switched off anytime you are modifying wires - don't do this "hot".
What to do with those ground wires
The deal with 2 ground wires is they go to different parts of the lamp.  They both need grounding, but one should go to the metal chassis of the lamp, yes?  Which can get grounding via the mounting screws.
(by the way, switches can also do this, but receptacles can't unless they are labeled "self-grounding" or certain other conditions are met.)
So if one of the ground wires  goes to the metal lamp chassis, attach the 2 grounds to each other and you're done.
"But I'd like to wire it up out of an abundance of caution"... let's pause to be clear about this. You can make redundant routes with safety ground, all you like.  Please do.  But DON'T do it with neutrals! Neutral is not ground, and it follows different rules.
Anyway, if you have a plastic/wood lamp body, or you want redundancy, yes - you can attach it to the metal box.  There will be a hole tapped #10-32 in the back of the metal box.  Possibly with a screw already in it, possibly a green screw. You can put 1 wire on that screw.
"But I have 2 wires" -> pigtail.  Or use a ground clip or drill/tap a second ground screw.   Ground screws must have thread pitch -32 or finer.  (32 threads per inch or finer, or 0.8mm or finer).
You cannot put a ground wire under a mounting screw, and you cannot use a sheet metal screw to add a ground wire (unless the sheet metal screw is ultra-fine thread #x-32 or finer).
Update based on your 12/9 info
Do not connect multiple hot wires together unless you like fire. What we've had you do so far is testing based on educated guesses. That is not the same as "blindly trying random stuff", that would be very wrong-headed.  Never blind experiment with electrical.  Some things go boom, and lots of things will create a situation where the device apparently works, and then kills you.
Your testing provided good data.
As expected, the red wires are "just passing through" and are providing always-hot to some other location.  Tapping these is pointless unless you want the light burning 24x7.
It's clear the orange wire is the correct wire, since it makes the dimmer power up.  The fact that the lamp won't light is a completely separate problem related to incompatibility between the light and the old dimmer.  Not every LED works on every dimmer (most do not, actually).
The blue wire was clearly never used.  Don't mess with it.
12/10 comments

4th attempt: Similar to 1st attempt (using orange wire as hot), this time used a GE LED BR30 10W bulb, when push the dimmer switch, the indicator is flashing green light, the bulb is lighting but very very dark. The switch CAN'T make it lighter, or I should say "not really controllable". (I thought the switch might be broken)

And this is no surprise.  Dimming is not magic.  It's complicated and very, very ugly because it's chained to a throwback technology from the 60s that was designed to make dimmers cheap.  If you got into the gory details, you'd go "Wowza, no wonder it's so hard to get LEDs and dimmers to work with each other!"
They actually have to add extra features to LEDs to make them dimmable.  Those features add a few bucks to the price of the LED, so if you shop on price, you won't get that feature by luck.

5th attempt: used a GE 52W incandescent bulb, everything worked out as expected! The dimmer wall switch is fine actually.

Congratulations, you've validated the dimmer as functional.  It's been incompatible with (most) LEDs all along.
"But I want LED up there!" -> I agree.  However you'll have to carefully search the marketplace for an LED light and a switch/dimmer that are certified to be compatible with each other.  Most dimmer manufacturers make lists of LEDs they've tested with, and better makes of LEDs which are designed for dimming often list dimmers they've been tested with.
Note that being a better make (e.g. GE) doesn't make it designed for dimming.  Being designed for dimming makes it designed for dimming.


Should I seal around the base of a bath/shower?

I would caulk any joint between fiberglass and tile. Some pre-made fiberglass kits have ways to overlap and seal the joint, but that doesn't appear to be your situation. Water coming out of the shower will be much more significant than any moisture that makes it through the tiles and grout.

That said, if moisture eventually deteriorates the walls and tiles, the best option is to replace the wall and then use a waterproof membrane that prevents any moisture from getting to the wall.


How should I finish the area around the gas line for my range?

You should have them come back, remove the valve, and install an elbow and a short nipple so the valve is outside the wall (make sure it's out far enough so that it's outside the finished wall). Then have them install the valve again.

If you know what you're doing, you could do the work yourself, but I don't recommend it.

Unfortunately the pipe bends the wrong way after the last elbow, otherwise you might be able to give it a quarter turn so that the elbow pointed out into the room. In your situation, however, this would loosen the joint, so it's not recommended.


Two hall lights not working with light switches

It sounds like a 3 way switch setup, use caution when working with 3 ways because there can be power and the light is off (no return path)and you can get shocked by providing a path to ground.
  I would start with the 2 loose white wires that are twisted connecting them to the new fixture black and white. then checking positions of switches that is the most likely solution.
I have seen 3 ways wired dozens of different ways and this is one.


How do I find studs when stud finders won't work?

Do you have any high powered magnets? like the rare earth neodynium magnets? If so you can probably rub one around the wall until it attaches to one of the nails in the studs. Or you can try thumping on the wall, a stud will sound alot less hollow versus empty drywall. That's how I've searched around in the past.


How do hardwood flooring expansion gaps work?

It's more accurate to say that the wood fibers swell rather than the wood moves. A board which is nailed down will still swell and contract around the nails, generally leading to a larger hole and squeaky floor. The nails hold the floor down and prevent gross movements, such as the floorboards sliding around underfoot.

Another key point to grasp is that boards swell along the growth rings in an amount proportional to their size. For practical purposes that means they really only have noticeable changes in width and it's a couple of percent of the width of the board. Adding an extra 1/64" to any individual board isn't a big deal, but it can add up across a lot of boards.

The gap is really about averting disaster. You're a board soaking up humidity. The tongue and groove joint gets a bit tighter, taking up some of the slack. Nail holes enlarge or nails bend slightly as you shove your neighbor aside an imperceptible amount. The floor remains flat and all is well, unless you're tight against the wall to begin with. In that case boards swell, and they press on their neighbors. They can't move sideways or down, so they go up. Boards cup, edges rise, the floor is warped.


How to solve new condensation in bathroom exhaust fan ducts?

Given all the experts that have looked at this first hand, I am hesitant to suggest a hypothesis based on other situations I have seen.  Also I live in a dry climate, so forgive me if I miss something obvious to everyone who is actually there in New Orleans.

As you know, condensation is the result of warm humid air contacting a cooler surface which is below the dew point.  From your description, you probably have slightly negative static pressure in your house and warm humid make-up air is being sucked through particular exhaust vents that connect to the outside.  That the problem became less severe when additional dampers and insulation were installed supports this hypothesis.  Unfortunately, short of a completely air-tight seal, warm humid air will continue to infiltrate through these paths as long as there is negative static pressure in the house.  Even a slow rate of warm humid air infiltration will eventually make every cool surface in its path wet.

The central blower on a system naturally makes slightly negative pressure in a house due to imperfect ducts that leak in spaces that are not open to the return(s) of the system (under the house, for example).  Any air that leaks out in such locations must be made up somewhere else, in this case by pulling a little outside air in through your bathroom exhausts.  The same situation occurs if the structure is somewhat leaky and the bathroom exhaust ducts are relatively close to the system return.  Return air flows via the path of least resistance and it may be easier to draw some air from a nearby bathroom exhaust than to draw 100% of the air from the far reaches of a house if remote supply air can more easily leak to the outdoors.

A relatively easy fix could be to give the return on your central air handler a controlled path for make-up air.  For example, you could duct a small outside air inlet directly to the return of your central unit, adjacent to the main return with a balancing damper so you can make final adjustments.  The outside air duct should probably be taped or sealed as well as insulated from the cooler temperature of the house.  It would also need to be small enough not overwhelm the main return or affect your energy consumption too adversely.  With a little make-up air provided directly to the unit from outside, your blower should stop sucking make-up air through your bathroom and dryer ducts.


Buy another 2x4 that is straight.  If it is for a workbench top you should be buying the best quality you can find which might cost $2 more.


Don’t start changing the wires!
Those pens are not a good way to troubleshoot.
Don’t start shotgunning parts without some basic troubleshooting.
For example I have a 3 speed fan that worked great all summer. One cool day we turned it off, another day it would not turn on at any of the speeds. I unplugged it opened it and spun the blades , they were stiff, it did not turn a full 360. I dribbled some light oil in the bearing close to the blades while turning by hand it freed up. I continued very slowly adding oil and spinning , wiped the excess oil and put it back together. The fan still works every day my grandson turns it on after school to see if it still works.

In my experience small fan motors fail because of dry bearings almost never the switch or capacitor. I have brought dozens if not hundreds of fans to life using light oil (will get slammed but wd40 works to get thing moving) 3 in 1 is better but a simple 30 weight oil will also work and last longer but takes a little get to get things free.


How to build a quick-and-easy wood ladder?

building a make-shift semi permanent  ladder is not a great idea for a couple of reasons.

First: It is very possible that your homeowner's insurance will insist it be removed or cancel your coverage.  I know this for fact as my insurance company (Good Neighbor) did an informal walk around my house and discovered a homemade ladder going from the sunroom roof up to the second floor roof. I had built it strong and attached it to a back wall in order to get up on the highest roof to remove snow. My agent called and explained the situation. a homemade ladder cannot be certified safe for a fire escape and by being permanently attached to the house invites unauthorized use and opens the Insurance company to liability.  Needless to say, they insisted I take it down.

Second reason: Although it may seem safe and secure at first, anything could happen. 2X4's as rungs could split. the angle may be bad and you might fall off.

Last reason: None of your friends here at SE want our favorite Yurt builder to get hurt.


Were my pipes frozen or was my pilot out?

If the heat source is off on the water heater, but no valves were closed, water will still come out of the hot tap. It may even still be warm-ish if you have a tank water heater, depending on how long the water has been in the tank with no heating. If no water is coming out, or water is coming out more slowly than normal, that could be an indication of a frozen pipe (it could be other things, too).


Outside electrical outlet doesn't work after pressure washing

That may not be necessary. You may have tripped a circuit breaker or a GFCI device.

First see if the breaker to that outlet has been tripped.
If the breaker is not already off, turn off the power to that outlet.
Confirm there is no power on the case by touching a no-contact tester against it.
Carefully remove the cover over the outlet.
Again check there is no power to the wires on the outlet.
See if there is any water in the housing.
If so let it drain, mop up with paper towels, and let air dry.
See if there is any sign of scorching or melted wire or insulation.
If there is, you need to replace the outlet and maybe even some wiring.

Once you are sure it is dry, before you replace the cover, you can try to reset the outlet. All modern outdoor outlets should be GFCI, with a device in the outlet itself, somewhere back downstream on the circuit, or at the main panel.

Turn the circuit breaker back on, and then find the GFCI device and reset it. This may solve your problem. If not, you may need a new outlet or GFCI device. If there is no GFCI device in the circuit, by all means replace the outdoor outlet with a new one.

If the seals around the outdoor outlet cover are not in good shape, you may want to replace that as well.


How do I build a scratch-resistant computer desk for filming?

Look up DIY concrete countertops. Pretty easy and strong. You can find someone to weld a desk for you that will look modern for next to nothing out of square tubing.


Removing old thermostat when replacing electric baseboard heaters

Your plan to connect the wires bypassing the old thermostats is a good one and it is code legal.

Make sure to turn the breaker(s) off and test to be sure both legs are off.  I have found some 240 volt units that the thermostat only opened one leg.

Make sure to use the proper size wirenut or insulated crimps for the size and type of wire.  If aluminum wire is installed, make sure to use deox / noalox or some other type of inhibitors and the connectors rated cu/al for the size wire.


Adding recessed lights to existing ceiling fan connection

At the Light

Connect the white wire that leads to the recessed lights, and the white wire from the fan/light to the white wire in the ceiling box.
Connect the the black from the recessed lights, to the black ungrounded (hot) wire that's controlled by the dimmer.
Connect the red wire from the fan/light, to the red ungrounded (hot) wire that is not controlled by the dimmer.
Connect all the grounding conductors.

At the switch

Connect the LINE wire (probably black, but depends on manufacturer) from the dimmer, in with the black wire from the feeder cable.
Connect the black wire from the armored cable, to the switched (probably red) wire from the dimmer.
Connect the ground wire from the dimmer, with the other grounds in the box.

This should allow the dimmer to control the recessed lights, and the remote to control the fan/light.
Of course this assumes that power comes to the switch first, and one of the wires in the cable is always hot.
Based on the info you've provided, it should look something like this.

According to the documentation for the dimmer, the black lead is LINE and the red lead is LOAD.


Repair will certainly be much cheaper than replacement. I recently installed a new garden window, which was oly 32x36" and the window cost over $600. Yours is even bigger. I'm guessing a local glass company could replace the broken glass for ~$200 or less--certainly no where near the cost of a complete replacement. Good luck!


What kind of backing should I use for a glass mosaic backsplash?

Here are some good points against using plywood, the source is talking about tiling a floor but most of the points are valid for walls as well.

In my opinion it's better to go the "overkill" route, then have to redo the job in the future because something didn't turn out right.

The cost difference between plywood and cement board is negligible, so your not going to save any money using plywood (unless you already have it).

Do the job right and use cement board, when you don't have any problems and you can enjoy the tile for years to come you will never regret the decision.


Should I agree to have more insulation added to my attic?

Good question.  First off, there is no "code" requirement that would mandate adding insulation to a 6 year old house. The current standard in new construction is to try to achieve a R-42 in attic spaces. Adding more insulation to your R30 is not a bad idea, however I have a few questions for you. What kind of insulation do you currently have installed there now? What are the dimensions of the space and style of house and source of heat and A/C.

Adding more insulation is almost always a good long term investment, but before I would trust a sales pitch from a door to door vendor, I would investigate alternate routes. If a DIY project, costs to simply add a layer of R 13 or R19/23 fiber glass blanket over my existing insulation.(assuming it is also F/G blanket style). I would also seek quotes from a couple of reputable energy conservation/insulation contractors in your area. A good contractor will ask you the same questions I have, and ask about your energy costs now, then calculate the potential energy reductions in hard numbers or percentages and expected pay back period. Some energy audits are offered at a reasonable fee or even free and address several aspects of comprehensive energy savings in the home. It can be amazing what a little caulking, joist/wrap box insulation, weather stripping, hot water conservation methods and increased attic insulation can make in your total energy picture. Does your state require a professional license or certification for this kind of work? Be cautious and seek a trusted professional opinion.


Can fill hoses be reused for a new washer?

"what is the justification for not including them as a matter of course?"

there are numerous choices when it comes to type and length of hose. Cheaper rubber hoses, more expensive stainless steel braided jacket rubber hoses, lengths from 4' to 12' long, etc.

"Can old fill hoses be reused? If not, why not?"

They certainly can be reused. If you are confident enough that they are in good shape then feel free to use old hoses (you should replace the washers at the end connections).

The downside is that, unless you turn your water supply valves off every time you leave your house, an old hose that fails can easily cause catastrophic flooding of your home. You need to make your decision based on a risk assessment putting the cost of new high quality hoses against the chances of and cost of a hose failure.

I bought brand new supply valves with quick 1/4 turn ball-valve construction to facilitate easy shut-off, and the best quality braided stainless hoses; and I shut off the valves whenever I will be gone for more than a day, because I do not want to come home to a flooded house.


How do I cut a hole through vinyl siding?

Cutting the vinyl siding is easy. A hole saw, tin snips, etc, will slice right through it. When we cut with a circular saw, we often install the blade backwards to minimize ripping and tearing of the vinyl. That said, the hole is the least of your effort. You need to be sure the weather stripping and siding itself is properly done to keep the siding water tight. See this answer for a full description of how to handle the tyvek, installing J-channel around the opening, and remove/reinstall the siding. One important consideration is that vinyl siding expands and contracts, so you don't want to make a fixed hole that fixes the siding to the house, otherwise you'll risk warping and buckling.


How to set up home network w/ fiber from street & unterminated Cat5e in garage

Without knowing more details, your plan is reasonable. Network equipment in the garage is not ideal, but not terrible, especially if insulated. On the other hand, if you live in a hot climate, the heat in the summer will be terrible for the gear. Cold is much less of a problem, though extreme cold would be.

One minor change is to add a patch panel between the switch and the drops to the rooms. This allows you to punch down all of your cables, rather than terminate them with jacks by hand; punching down is much easier for the novice (and the extra cost is minimal). You then run short cables (you purchase, not make) between the patch panel and switch. See my answer to a similar question for more details about using a patch panel.

Depending on how the house is laid out, and how much slack there is in the unterminated cables, you could take the whole bundle and move it somewhere inside the house. If there's little slack, you may just move them to the other side of the wall they're currently on. All my network and CATV stuff is in the master closet for this reason.

Brand recommendations are off-topic here, so I won't comment about specific routers or equipment. As far as testing the network, you should just need the gateway connected to test the fiber install. The rest is on you and can be done later. A simple network tester (example only, not a recommendation) will verify all your punchdowns are made securely, though that won't verify gigabit speeds.

As for multiple wired devices in one room, yes, a small 4-8 port unmanaged switch will work just fine.


Water pressure buildup causing water meter to turn

Heat and cold cause air expansion and contraction if your system is wet it may have a relief valve bumping excess pressure down a drain, If it is a dry system I would make sure the flapper at the wet/dry division is not leaking by this can cause all kinds of trouble but these are usually on large systems, smaller home health care systems I have experience with are wet and as the water in the plumbing heats the relief vents Down a drain. This is much better than a over pressure that starts leaking in the living space.


Is it possible to shorten the flue/chimney of a range hood?

Depends on the hood. Some come with a telescopic shroud, to go bigger, but not smaller. Check the dimensions on the box. Whatever the small dimension is, has to be able to fit.

Or open the box to see how much of the shroud you could cut off, having grabbed an elbow from another isle in the store to see the ultimate clearance requirements when assembled. Flexible might save you an extra inch or so, but is ideally avoided.


What prevents mortar from being compressed with the weight of courses of brick?

Mortar is used much thicker than cement and even thicker than thinset.
Time
Bricks aren't that heavy and generally you aren't just stacking one on top of another.

The only time that you would ever have a weight issue is when building a column or post and if you were skilled enough to climb rows so fast that your previous stuff has no time to set.  I am not that good so I have never had that issue.  It takes me 3-4 minutes just to butter each brick even.  I imagine someone who is really good gets a lot of downtime when doing a post or they do a few posts at a time.

Also I imagine that someone asking this question has too much water in their mix.


Adding a new dimmer switch to old wiring?

The white wire to the switch should be the hot feed if it is wired according to code. Connect the white wire to the top black wire on your dimmer and connect the black wire from the cable to the other black wire. Connect the green to the bare wire on the cable (and to the box if it is metal.)

Make sure your light fixtures are dimmable and the dimmer is the right one for the type of lighting you have.


Can anyone identify what brand/company makes tracks for these curtains?

These appear to be Ripple Fold curtains.

It is a proprietary system of curtains which allows for hanging a wide variety of fabrics without having to create gathers in the traditional way.


Can I draw 240v out of this configuration?

The feeder wire has a black, a red, a white, and a green so this suggests there are both legs present, i.e., 240 V is present.

There appears to be a double space on the right open for a 2-pole breaker. A 60 A feeder breaker should support the addition of a 2-pole 20 A load depending on the actual loads on the other circuits in this sub-panel.


OK... what you need to do is:

1) after turning off the power, remove the two screws above and below the middle socket of the vanity lights that are not working. Examine the wires in the junction box for any burn parks are disconnected wires. Redo any connections that look bad.

2) Remove the cover from the other side of the vanity, the side that's working, and examine the connections for the wires from other lights to where they hook up to the white and black wires from the switch. Look for burnt or disconnected wires. Redo any connections that look bad. Put a light bulb in each side and turn on the power and flip the switch and see what happens. Good luck.


How to fix loud foghorn noise from shower when going from hot to cold water?

With the flow on the cold being the issue it sounds like water hammer. I have seen extreme water hammer with very tiny flows but it is much more common with high flows.
The 2 solutions I know of for water hammer are.
Strapping the pipes that are chattering, if you have access a couple of straps to keep the pipes from chattering will quiet it down.
Add a water hammer arrester these are devices you install on the water line that have a chamber spring loaded or air chamber that cushion the flow issue. For best results they need to be on the line that is chattering but I have seen one installed at the toilet fix a shower & sink issue. These devices cost between 10-20$ in the US and since most plumbing is not accessible would be my first thing to try.


I'm really not sure why there are three bottom plates. Even if the treated board is a sill, doubled bottoms are not common, in my experience. However, I can't think of a reason why you couldn't insulate that as you describe.


Since your product has actually cleared all the EU safety standards and then some (TUV follows UL's standards generally), I recommend keeping your safe product all-safe.  That precludes using the cheap Asian junkstream coming out of Alibaba and blasting onto AliExpress, eBay, Amazon, banggood and other turdmeister outlets.

You want drivers which either have a listing from an NRTL, or component listings such as Underwriter's Laboratories ЯU mark.    You can make do with the "CE" mark if and only if the driver was shipped in a container to a bricks and mortar manufacturer in the EU, and then distributed to EU electronics distributors or to you.

Dropshippers like Amazon's warehouse do not count; anything from Prime equals direct ship from China. That means the CE mark is no good.

The CE mark is a promise by the manufacturer or importer that the item complies with EU safety standards.  It has no bearing on anyone outside the EU.  So the manufacturers simply fake the mark, and direct-ship it (including via dropshippers). That makes YOU the importer.

Dimming LEDs

LED drivers do not naturally dim. They consider triac dimming to be line noise, and they do their level best to ignore it. This could fatigue and burn out a non-dimming-rated LED driver.

Triac dimming uses a cheap hack that makes the dimmers cheaper, but was only ever expected to work on incandescent lights.  A "dimmer-friendly" LED driver is generally one which is hardened and also has some intelligence to listen to the AC waveform and "reverse-engineer" what the triac dimmer is trying to do.  It then commands the LEDs to dim to that level, such as with PWM or current limiting.   This scheme is tomfoolery.

Triac dimming is cheap residential grade nonsense.  Commercial lighting requires more efficiency, so it has always used better tech such as fluorescent, which couldn't possibly use triac dimming.  So they have had a standard, for decades, called "0-10V" - principally used on fluorescents at the time.  A signal is sent on separate wires from the dimmer controller (which need not be the light switch) to the LEDs.  The separate wires run in a separate cable that may or may not need to be part of the AC mains wires.  You have to follow your local electrical code's rules for low voltage wiring.

All that to say, if you're unequipped to run additional wires in the walls, you might not be able to use 0-10V dimming.  But it is definitely the more "pro" way to do that thing.

Matching your spec

LEDs are driven "constant-current" because they are not linear; they have a very steep voltage-current curve that is influenced by age and temperature. (hotter = higher current at same voltage, causing a thermal runaway situation).  Constant-current is essential to best performance.

"Constant-current" (or to be more precise, varying current) is also the best way to dim LEDs.

So, the critical spec on your LED driver is the 1350 mA figure.  You could use a driver with a lower figure, but the LEDs will be dimmer if you do.

It will take a certain voltage range for that to happen; the voltage changing based on temperature, age, etc.  The manufacturer believes that happens in the range of 27-42 volts.  You need a driver capable of functioning in that voltage range.

I generally go to electronics supply houses like Mouser or Digi-Key for LED drivers. Not sure who the players are in your country.


Attaching drywall to cracked/sagging plaster ceiling?

The plaster is sagging probably due to issues with some of the lathe boards above it.   Those need to be repaired.

If you have access above this you could just knock these totally out and reframe with 2x4s.   This would probably be the quickest way.

As far as mess...   You are thinking about this wrong.   Demoing might be a mess.   Sanding the mud for the new drywall will be 10 times worse for your house.

My advice is knock out the ceiling.  (this will take minutes)   Then reframe and then add drywall.   This space will have to be totally emptied out.   If you are quick you can get drywall up with first coat of mud in day 1.   Day 2 you can add second - final set of mud (if you are really good).   This will take at least two days to dry.   Day 4 you are sanding.   That is best case scenario.   Room will have to be emptied and doorways will have to be tarped off from rest of the house.


How do I fix a leak in a fiberglass water tank?

When I worked in a fiberglass piping company we used a fiberglass resin mixture that was thickened with a product called aeroseal. This made the resin extremely thick which allowed us to fill spaces between two fiberglass pipes. The mixture was then sanded and fiberglassed with resin and glass both inside and out.


Proper Orientation for Plywood Subfloor under 3/4" Hardwood

Your current plywood is suitable for hardwood installation.  I do not ever like to use 1/4 subfloor as it is brittle and when screwed sometimes doesn't lay flat.  If I added to your subfloor I would at least put in 1/2 inch but like I said you don't need it with 16" OC.  Note that a thicker sub might have benefits but at the same time you are adding weight to the joists.
Depends on area of country and moisture levels.  CDX is fine in most places.
I would not try to match the current subfloor.  I would do the opposite.
I do not ever attach additional subfloor layers to joists.  When the joists swells - and they will in 80% of the world - your sub will be pulled or pushed and then you will have a screw or nail that is working its way out and possibly squeaky floors.  The whole reason for the second layer is extra inflection levels.  By attaching to the same thing you get the same thing just thicker.


What to do when the cold water valve on the water heater is welded on?

I think you mean soldered? A picture would help, a lot. There should be a flexible line going from the valve to the pipe system that detaches by loosening the hex-nut fitting. If there isn't a flex, you will be cutting it out and installing it properly, so that swapping out the next tank in ten years doesn't require calling a plumber, again.

I'm guessing yours looks like the one on the right in this picture. They should both look the one on the left. If this is your exact situation, I'd cut it out at the level of that other elbow on the hot side, install a valve there (perhaps mimicking that short horizontal run, to insure space for a power-vented unit's exhaust blower -to be installed in the future) and attach it with a new flex.

Picture source: How to Install a New Hot Water Heater, hubpages.com

The fitting could be heated with a blow torch to dissemble it for just a quick install of a dip tube and reassembled with no additional parts, PROVIDED, you are really good at sweating used copper fittings (not easy). If you're not and are going to have to call a plumber, I highly suggest having it re-piped as described so that you can swap it out yourself at some point when it dies.


Assuming you don't want to/can't remove them completely, (i.e.- back to an existing junction box, or all the way back to the breaker box), you need to properly terminate them (capped with wire nuts) in an accessible junction box.

In other words- install a junction box in, put wire nuts on the wires, install your cabinets, with a hole where the junction box is, and put a cover plate on.


Do I have to install a vent to add a bar sink in my basement?

Do I need a separate vent stack for my kitchen sink?
... in my state (VA), the allowable distance between a 1 1/2" drain trap (standard size for a kitchen sink) and its vent is 6 feet. If your trap is farther from the vent than that, then you should consider adding a new vent or an air admittance valve.

If your local codes allow them, the 2" pipe may serve as a wet vent. According to the IPC an X size stack can handle Y number of DFU.
1.5" : 1 DFU
2"   : 4 DFU
2.5" : 6 DFU
3"   : 12 DFU
DFU or Drain Fixture Units, where the UPC allows for bar sinks to count as 1 and kitchen sinks to count as 2.
So long as these are the only two fixtures discharging into the 2" pipe, you're within nominal code not to add a vent but you still need to check your local codes.


From the similarity of the lines, I'd say you pulled something out of the old 2x4 (nails) and dragged them across the board, perhaps as you twisted and pulled to separate/remote the board from wherever it was before. I don't believe there are any insects that travel in perfect unison like that.


How to easily fix/replace central vacuum wall mount bracket?

I would use some 5 minute epoxy to glue in two little pieces of plastic or wood.
You  may need to carefully  clean up or remove the old remaining parts of the screw hole tabs with a small hacksaw blade or an oscillating saw. Careful not to cut the wire.
Once the epoxy is set then you will need to drill the appropriate size hole for the  old or new screws. The dill bit should be as wide as the body of screw but narrower then the threads. This is so the threads will grab the wood/plastic but not split it.


To which extent can outside walls make a room cold?

An association of insulation suppliers claims

More than 40% of all the heat lost in an average home is through the loft space and walls
Up to 45% of heat is lost through uninsulated solid walls
More heat is lost through walls than any other route – approximately 33% in an uninsulated home

Obviously, we need to take into account that they are not a disinterested party but this does support the idea that the more external walls a room has, the more heat it will lose to the outside in cold weather.

The solutions, unsurprisingly are

insulate the walls (and ceiling, and floors too)
install heating.

Insulation depends on the type of wall construction - which differs markedly between the USA and UK and other places.

See http://www.engineeringtoolbox.com/heat-loss-transmission-d_748.html


You really need someone to look at this in person, not through an internet straw. Some notes that may help...

Builders almost never use 2x10 for non-load-bearing headers. They're expensive and it's wasteful. That doesn't prove anything here, though.
The drawing shows the primary bearing wall being at the back of that closet. That doesn't prove anything, though.
You don't report seeing or hearing settling when you removed the header support studs. That doesn't prove anything, though.
You could investigate the headers over the adjacent hallway and along that plane to see if they're load-bearing. That doesn't prove anything, though.
You can examine the lower level to see where loads are transferred through the basement walls or posts to the footings in the foundation. That doesn't prove anything, though.

It's the accumulation and analysis of such clues in aggregate that leads to a reasonable and safe conclusion. We can't do that from here without a protracted and cumbersome conversation. That's not really what this site is for.
Good luck.


Adding another line/wire in metal conduit

You need to determine first as asked in the comments, do you NEED a neutral?
That would depend on the car requirements. Refer to the car manufacturer's manual.
The power supply is just dumb power.  All the fancy charging logic circuitry is in the car.

NEC chapter 625 has specs for the charging system. Note it has to be GFCI, possibly AFCI too, depending on where it's installed.
Free code lookup here-
https://www.nfpa.org/NEC/About-the-NEC/Explore-the-2017-NEC?openpage=106&access=open
(free registration required)
unfortunately without search function- Chapter 9, tables 4 and 5 have your answers about conduit fill.

Chatty explanation here-
http://www.codebookcity.com/codearticles/nec/conduitfill.htm


Why would a patio heater slowly die out over time?

It sounds to me like a restriction at the regulator, not the control valve. You mentioned that the previous owner had done some work on it, make sure that he/she did not replace the regulator with one that does not deliver the design flow/pressure. In this case, adequate flow/pressure depends on proper regulator back pressure setting (they are rated in "inches of water" back pressure). If the regulator setting is too low, it will not deliver an adequate flow/pressure of gas.

If this is the case, the initial proper operation followed by diminishing performance is explained by the volume of gas in the 8' tall hose assembly, with a slow reduction in adequate volume being delivered by the undersized regulator. I had your exact problem when I attempted to swap out a leaky patio heater regulator with a BBQ regulator that had a different pressure setting.

Like this:

Regulator is initially open because of low (zero) downstream pressure.
8' tall hose fills with gas until rated back pressure downstream of regulator is reached, regulator closes.
You open control valve and light heater, regulator opens as downstream pressure drops.
Damaged, defective, clogged, or undersized regulator cannot supply enough gas to maintain proper flame height as pressure drops, but does stay open and deliver gas according to it's pressure setting, which is not enough for adequate flame propagation.

It's worth checking, anyway.


What tools would I need to make a wood accent wall?

If you are fixing this to a wall with drywall on it, you will need 2 1/2" long finish nails to toenail it with, at the tongue edge. If you are staining it, DO NOT face nail it. If you are painting it, well nail it anywhere you please. The wood you are planning to use will work very well, make sure it will give you the look you want by making a sample, say 3' square and place it so it will take on the light that come from windows, lights, what have you. This is done at the wall you are planning to cover. The surrounding colors of the painted wall or stained cabinets that are nearby will play into the choice too.

The saw you linked to is a good saw, maybe more than what you need to do the job, It is made for heavier material but it will still cut small trim pieces too. I have used another brand that was made like this and it cut very small pieces too. It will serve you well for many years to come if you get it. Be mindful of its cut capacity, it looks like it has a capacity if 5 3/4" at the 90 degree setting, it will be much shorter on the 45 degree setting. If you are making all square cuts, no problem. I would consider getting an 8" slide compound saw, larger capacity, lightweight. I have an old Hitachi 8" compound slide, I have owned for the past 15 years, worked it to death, replaced the armature once, the brushes twice, did it myself, still doing a great job. Here is a link to the modern replacement of what I have been using


Adding always hot receptacle to a ceiling light that’s on timer

At some point, you need to split the power for the receptacle separate from the light. Where/how you can do that depends on whether you have:

Panel->Timer->Light
or
Panel->Light->Timer (a switch loop)

The first method is what I instinctively think of, but depending on the design of the how building and when/how the light was added, you may have the second - a switch loop. If you have a switch loop then you can split the power at the light and everything is easy. But if not, them there are two ways to get power for the receptacle:

At the current timer location. This is normally the best way, but it requires running a new cable from the timer junction box to the receptacle. That may be easy, or it may be quite difficult.
At the light. This is actually quite easy if the light is not on a timer. As @Mazura suggested, if you can replace the existing light fixture with one that has a photo sensor (sometimes called "dusk to dawn") then you can:

Split the power in the junction box that supplies the light. Depending on how the light is installed, you may be able to add a split (pigtail wires) in that box, or you may need to install a new box next to it. But either way, everything can be close together and you don't need to run a new cable through the wall.
Either in the same junction box or in one next to it, install the receptacle for the security camera. Normally I'm not a big fan of receptacles in hard-to-reach places like a porch ceiling, but in this case that is exactly what you want, so that the power cable to the camera is not easy to reach. (I've seen a porch security camera with a wire hanging down to a wall wart plugged into a standard-height receptacle.)

Another advantage of changing the light to a photo sensor is that you no longer have to worry about adjusting the timing over the course of the year.


How to run single ethernet (no PoE) in trench through garden?

The tower up the hill might take direct strikes before you, but those strikes might make big surges on the ground, so long story short, always use surge protection (or better, all dielectric fiber).

You don't necessarily have to meet the code requirements for electrical installations with your direct buried ethernet cable and I wouldn't worry too much about 6" of burial except under a gravel driveway.  I don't think that will survive long.  I don't think PVC will help much, I'd sleeve it in galvanized rigid metallic conduit across the driveway and hope for the best.  (I am assuming this is just for home networking etc. and isn't anything life and death.)


If you are sanding the paper tape, you definitely need more mud. So put on more mud.

Removing it would not really help, it would just make more of a mess you have to mud over.

I suggest 3-4", 6-8" and 12" for a progression in drywall "knives" (a coat with the small one, knock off only the high points, a coat with the medium one, knock off only the high points, a coat with the big one, if there are significant divots when sanding after that (there should not be), stop and recoat to fill the divots.


Are there door knobs specifically meant for outdoors?

Normally anything that has keys that come with it is meant for outdoor use.  And almost all of these are made from non corrosive metals.

I can't think of any house that I have ever looked at that had a rusted out door knob and everything else was in good shape.


What's the difference between "Framing Lumber" and "Framing Studs"?

Studs are cut to length at the mill so you can build your 8’ walls without cutting the ends off the top and bottom plates with studs make a quick tilt up wall, the rest is true 8’ 10’ 12’ .  Note if remodeling verify length prior to building a wall.


Wiring a fan to a 3 wire switch off wiring question

You can't generally tap a 3-way complex like that.

-
That is a 3-way switch. It's partner to another 3-way switch in a different location. Further, it is on a "spur", meaning the only wires that are here are 2 travelers (red and black) and a hot wire (presumably always-hot).

Given that it is hot, the white wire must be re-marked with tape, paint or sleeving to indicate that.  Typically black is used, but other legal hot colors are allowed. The two traveler wires, it's my advice to mark those both yellow since they go on brass screws.  Markings should be done the same at both ends of the cable.

Anyway, since you want the switch to control a fan, you will need switched-hot and neutral.  You don't have either one of those here.

Possibly: Flip it around

It really depends what the wiring is in the other 3-way box.  It might be possible to reallocate the wires so that the white wire becomes a neutral, the red and black remain travelers (remarked yellow), and then you feed the fan onward from this box.  White would become neutral and switched-hot would be the "common" (black) screw on the 3-way.

You'd need some help with this at your skill level.

Hail-mary play: rearrange the entire 3-way circuit to be smart switches - only if other things are also true

Nowadays, there are "smart switches".  In some cases, they allow you to rearrange how the existing wiring is used.  This may allow you to get the wires you need here.  We'd need more info about the other switch box and whatever else they connect to.


One faucet doesn't work when it's really cold

As others state, fix it before the pipe bursts, and you have expensive water damage, possibly making the house unlivable.

Temporarily, you might try putting insulation over the outside of the wall where the pipe runs. You could try following the path of the pipe with a stud finder, though if it's plastic pipe, it might not show. Then make place bats of insulation outside long that path, and cover them with a wood frame to prevent that insulation getting damaged.


Use a spool to store them
They make a wide variety of wire caddies and spools intended for spooling up extension cords.  My "go to" is about 18" long, flat, and looks like this:
   ------+--------------------------+------
         |                          |
   ------+--------------------------+------
                  \------/

That thing being a handle.  You attach one end (they give a little hook for that and spool up the wires.  That's great for storage and easy unfurling.
However, to re-twist, the spool is especially essential. As you're spooling up the wire, when you hit an untwisted area, stop short of it.  Rotate the whole spool.  That lets you add twist to the wires as needed.


Is it necessary to remove old wasp nests?

Personally I had lots of wasp nests before, and after "exterminating" few of them I left them where they were. No more wasps in there. One thing - I used one of the "wasp killers" so that I was sure there will be no more chance to get wasps here. But one thing - if wast nest was removed there was a bit more chance that wasps get in here one more time building another nest. Try to use really good wasp repeller. Those chemicals do it right.


Installing a smart dimmer switch into 3 gang box

I think the kind of tester you are using is not accurate enough.

Here's a good way to find out which wire is HOT and which is LOAD on the middle switch:

turn off the circuit breaker
Turn off the left switch
Disconnect both wires from the middle switch and cap each one with a wire nut
Turn on the circuit breaker
Carefully remove the wire nut from one of the disconnected wires and touch it to the hot terminal on the left switch - if the living room recessed lights come on, that was the LOAD wire - mark it with a bit of tape
If the living room recessed lights do not come on, touch the wire to the load terminal on the left switch - if the eyeball light comes on then that was the HOT wire
Replace the protective wire nut before continuing
If no lights come on, try carefully repeating the test with the other disconnected wire
remember to turn off the circuit breaker again before continuing

These tests depend on your switches being wired correctly in the first place. If both wires from the center switch behave exactly alike, or if your testing trips the circuit breaker, your wiring may have errors that will require much more analysis.


Help running ethernet between floors, with double joists in the way

See this answer for more information on drilling through joists.

For your case specifically, you're able to notch (and angle drill) at a depth of D/6 and a width of D/3 at a time per joist as long as you are notching in the first or last third of the joist.

  IRC R502.8 Drilling and notching.

  Structural floor members shall not be cut, bored or notched in excess
  of the limitations specified in this section. See Figure R502.8.


Plug HRV (Constructo 2.0 ES) into power bar?

If by power bar you mean.

Then, Yes you can.

Make sure to wire up your plug correctly and properly. If it did not come originally with a plug then check if the wires are sat firmly within the plug.

  As per you comment. It is possibly true for cheap power blocks with no
  certification or valuation, so don't use cheap ones for lots of
  things.  If you are paying a premium price for a power block with
  surge protection and marked as 1800Watt then you can be pretty sure it
  passes all tests to handle this wattage. (beware of fakes)

For the second part, Yes you can also plug all your other appliances into the power bar.

You just have to make sure that the total combined wattage does not get excessive. As a guideline I would say stay under 1000watt constant usage.

The 1800watt means the power bar can handle a maximum of 1800watt but it does not mean you should push it to that limit.


How should I connect my light fixture in this ceiling box?

Wire nut two blacks together.  Push them back in the box.  Attach new fixture black to red. Connect all whites together.  Connect all grounds together.


Why is there a white powdery deposit in my swamp cooler?

That's just scale and mineral buildup. Evaporative coolers work by evaporating water; when they evaporate hard water that has minerals in it, the minerals stay behind. The better coolers have constant bleed lines or purge pumps to prevent this buildup by flushing it away. You can do it yourself by periodically draining all the water in the sump. Or you can install a bleed line or purge pump yourself.

But if you have one of the old coolers that uses thin aspen pads, know that you have to replace those pads at least every year. That type of older cooler requires a decent amount of maintenance; if you're not willing or able to do it, I would recommend replacing it with a newer unit that uses thick rigid media that lasts a long time instead of those aspen pads, and has a bleed line or purge pump to keep the scale buildup down.


What is the Best mixture ratio of Portland cement Quartz sand and bonding agent for under water application

Are you sure you don't want to be looking at a hydraulic cement or mortar rather than just Portland cement?

http://www.lowes.com/pd_41334-96-00924_0__?productId=3033247

Or something like this?  http://www.superior-industries.com/pro_patch_600_product_271.html

I'm not trying to advocate specific products or brands, but illustrating examples of products that are actually designed for underwater use.

If you were looking at one-off repair of loose or detached tiles, you might consider an underwater adhesive:  http://solutions.3m.com/wps/portal/3M/en_US/Adhesives/Tapes/Products/~/3M-Marine-Adhesive-Sealant-5200?N=5510818+3294314622&rt=rud


Not with the outlet on a spur with 12/2.
Worse, you cannot simply bypass the switch, unless there’s another light in the room under control of a switch.  Code requires every room must have a light switch in the usual location, and the switch must either operate a light, or a socket.


The pipe coming out of the floor is PEX, and its actually expanded and slipped over the brass fitting to form a permanent connection. This kind of fitting shouldn't leak are you sure the drip isn't coming from between the Valve and the Brass?  (The 'white plastic' is Teflon tape wrapped around the brass threads.)  The only way to tighten it is with two wrenches: one to hold the brass and one to turn the valve.


If the return air comes in through the bottom of the AC, then a drip pan is not possible. Typically, external drip pans are only used when leaking condensate would cause an issue to the structure, such as air handlers in an attic. In a basement or a garage (especially with a vertical air path), a drip pan is unnecessary.


What materials to use replacing a water damaged bathroom ceiling?

Do you want to have to replace it again if there's ever another leak? If yes, then use another inexpensive paper-and-gypsum-based product, such as drywall, green board, etc. If no, then use cementboard. Maybe overkill, but for a small bathroom the uncharge won't be more than $40 and that stuff can get wet till the cows come home and not complain about it! Once it's up, you can texture it, skim coat it, paint it, or whatever you were going to do to the drywall that you were considering.


Losing water pressure in water hose while washing vehicle

There are a few reasons this can happen.

Other uses of water + small lines

Depending on the size of pipes and the way it's plumbed in, it could happen if something/something else in your house was using water (dishwasher, washing machine, shower). This happens a lot in subdivision homes (which are built using the bare minimum amount of money required to meet code), where all the branch lines are 1/2".

Hose clogged

You can also check the hose when this happens: disconnect it from the hose bib (aka spigot), and see if that has a reduced flow as well.

If it doesn't, there may be something clogging your nozzle or hose.

Pressure regulator

You may also have a pressure regulator on your house (see pic below). These can have trouble if the supply pressure is below what they're set at -- I'm not 100% sure what happens but I'd bet it would reduce the pressure like what you've said.

They can also get clogged with debris (though unlikely with city supply) and sometimes fail for no apparent reason (though again, unlikely).


Why won't my washer spin even though it still agitates?

I'm not completely sure how the drive elements connect up on this. I know there is no belt. Gear box seems very unlikely. You should examine how the agitator attaches to the drive shaft below the top cap of the agitator. Sounds like it's slipping, and if that's the case, it may not be able to spin either. If it works differently than I think, it could be the clutch slipping. To get to the clutch is major surgery. You'd have to remove the agitator and would discover any slipping parts here on your way to the clutch any way.


Take the switch you bought back and get a 3-way

That switch is a 3-way switch (the term "common" as part of the labeling for the terminals is a dead giveaway).  Unfortunately, using a four-way as a three-way will probably confuse the next person to work on it, so it's better to take it back and just get a 3-way instead (it'll also get you some of your hard-earned money back as a return credit).

P.S. when you wire the new switch, use the side-screws not the back-stabs. It'll save you a bunch of trouble in the long run.


Why did my drill stop when trying to pilot a screw hole in framing lumber?

Without knowing anything about the building, I would first suspect you drilled (partially) into a steel pipe

or a nail plate

which is protecting wire, tubing, or conduit.

In my 1950s house which uses 2x4s from a bygone era (dense Douglas-fir), I have to predrill any stud into which I intend to drive a screw or nail.  Yes, a nail.  Otherwise the nail will bend or curl or the screw will snap.  I use a sharp 1/8 inch drill bit for pre-drilling.


Can I share the neutral in 12/3 cable between two GFI circuits with different current ratings?

What you're explaining is called a multiwire branch circuit (and has been discussed here many times before), which is where 2 ungrounded (hot) conductors will share a single grounded (neutral) conductor. There are special requirements for this type of circuit, which must be followed to insure safety. This type of installation is slightly more complicated when dealing with ground fault protection, because of the way ground fault circuit interrupters (GFCI) work.
Multiwire Branch Circuits
Disconnecting Means

NEC 2008
210.4 (B) Disconnecting Means Each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all
ungrounded conductors at the point where the branch circuit
originates.

This means that the breaker handles must be tied together in the service panel, so that if one breaker trips it will cut power to both circuits. This can be accomplished using handle ties, or a double pole breaker.
Legs
In multiwire branch circuits, each ungrounded conductor must terminate to different legs of the system. If this is not done the currents on the grounded (neutral) conductor will add instead of cancelling out, possibly overloading the grounded (neutral) conductor leading to a fire. Again, this can be easily accomplished using a double pole breaker.
GFCI
Ground fault circuit interrupting devices work by measuring the current on the ungrounded (hot) conductor, and the grounded (neutral) conductor.  If the currents on these conductors differs by more than a specific amount, the circuit is opened preventing current from flowing.  This can present a problem when using two separate GFCI breakers, because the current on the grounded (neutral) conductor will be the difference between the two ungrounded conductors.
Ungrounded conductor 1 = 13A
Ungrounded conductor 2 = 6A
Grounded conductor = 7A

In this situation, the breakers will detect a potential (false) ground fault and trip.  This can easily be avoided by using a double pole GFCI breaker. This is because a double pole GFCI breaker monitors both ungrounded (hot) conductors, and a single shared grounded (neutral) conductor.
Wire Size
The conductors in a multiwire branch circuit (like in all branch circuits), must be appropriately sized based on the load to be served and the overcurrent device protecting the circuit.
Receptacle Rating
NEC article 210.21(B)(3), specifies the receptacle rating based on the circuit rating.
Proper Installation
Now that you know more than you've ever wanted to know, here is what you need to know.
In the service panel

Install a 20A double pole GFCI breaker in the service panel.
Connect the bare (equipment ground) wire (from the circuit) to the ground buss bar in the service panel.
Connect the white grounded (neutral) wire (from the circuit) to the neutral terminal of the GFCI breaker.
Connect the white grounded (neutral) wire (from the GFCI breaker) to the neutral buss bar.
Connect the black ungrounded (hot) wire to one terminal of the double pole GFCI breaker.
Connect the red ungrounded (hot) wire to the other terminal of the double pole GFCI breaker.

At the first junction

Connect the black or red ungrounded (hot) wire to the brass screw on the receptacle.
Connect the white grounded (neutral) wire from the 12/3 cable to the white ungrounded (neutral) wire leading to the next junction point, and to a short length of scrap wire (pigtail) using a twist-on wire cap (or other approved method).
Connect the pigtail from the previous step to the silver screw on the receptacle.
Connect a short piece of scrap ground wire to the green screw on the receptacle.
Connect all equipment ground conductors together, and to the junction box if a metal box is used.
Connect the red or black ungrounded (hot) wire to the black ungrounded (hot) wire leading to the next junction point.

At the next junction

Connect the red or black ungrounded (hot) wire from the previous junction to the brass screw on the receptacle.
Connect the white grounded (neutral) wire to the silver screw on the receptacle.
Connect the equipment ground wire to the green screw on the receptacle, and to the junction box if a metal box is used.

Receptacle Ratings
If you used a 20A GFCI breaker in the panel, you'll want to use receptacles rated for 20A.  However, if you have more than one receptacle on a single circuit, you can use receptacles rated at 15A.  In a multiwire branch circuit situation, that means you'll need two receptacles fed by one ungrounded (hot) conductor to be able to use 15A receptacles. It's also important to be aware, that NEC considers a duplex receptacle as two receptacles.  This means you can use a single 15A duplex receptacle, and be code compliant. Though Because the overcurrent device is rated at 20A, it may be appropriate to use 20A receptacles throughout the circuit.
Daisy Chaining
If you are going to be feeding multiple receptacles off either leg of the multiwire branch circuit, you have to make sure that the grounded (neutral) conductor is unbroken throughout the entire circuit even when devices are disconnected.  This means you won't be able to use the "load" side terminal on a receptacle, to feed the grounded (neutral) wire through to another receptacle.
TL;DR

You'll need a 20A double pole GFCI breaker. Two single pole GFCI breakers will not work.
If you use a 20A overcurrent device, you must have more than one 15A receptacle on that leg of the circuit. Otherwise, you'll have to use a 20A receptacle.

As always, if you don't feel comfortable with your knowledge or skill level, don't be afraid to contact a qualified Electrician.


How can I cut regularly spaced 45 degree grooves in a piece of wood?

You could use a router set in a router table, with a crosscut sled set at 45 degrees.

Building a jig with a "pin" that fits into the previously cut groove, will make sure all the grooves are cut an equal distance apart.  The "pin" will be attached to the sled in some way, and will sit against the edge of the work piece for the first cut.  After the first cut, the "pin" will sit in the groove produced by the first cut. The board is then lifted and moved, so that the "pin" sits in the most recently cut groove. This process is repeated the length of the work piece.

I'd make a jig similar to this.


There are standard curtain rods for bay windows such as this one

There is also no reason you cannot use three rods, placed close to one another, one for each window.


Selection of Breaking Capacity in Circuit Breakers

The "6 KA" number (literally, 6000 amps) is based on being able to trip out at the maximum possible bolted fault (i.e. not having its contacts welded shut by the current).  There's really no point having a 25KA breaker when the delivery wires are incapable of delivering even 6KA of flow.

The current capacity of the delivery wires is decided by their size and Ohm's Law.  Any particular size of wire has a known resistance per length, and this can be multiplied by length to give the resistance of the service drop from the transformer.  That resistance, and the service voltage, plugged into Ohm's Law gives the maximum possible current.

For instance, some American power companies guarantee that their delivery drop wires will be sized so as to render current flow above 10KA impossible.  Thus, 10KA main breakers are legal in those services.  Since European services deliver twice the voltage (and presumably half the amperage), we can guess they use smaller service drop wires, and thus, have a lower maximum KA.

This has nothing to do with the voltage on the transformer primary.  If 13KV gets into your house's electrical system, that's what your grounding and bonding system is for. The 13KV is unlikely to flow 6 KA because it is coming off rather lengthy feed wires that have come for miles.  The resistance of those feed wires will be much too great for 6 KA to even be possible.

This isn't about lightning. Lightning is Thor's hammer, the Hulk can barely stop it, no molded case circuit breaker can.   A high voltage line like 13KV will have lightning arrestors, because otherwise, the lightning will find somewhere else to arc to ground, and when it strikes that arc, the 13KV will sustain the arc indefinitely.


Assuming you are talking about HardieBacker cement board, the manufacturer's SDS (Safety Data Sheet) recommends using an N-95 (minimum) respirator/dust mask. But there are other best-practices for preventing exposure to the dust (the dust contains crystalline silica).


I'm having trouble finding an exact match on the Artika site, and the Costco site (as usual) does not list all the products found in stores. The products that I checked manuals on the Artika site have no mention of the other wires.

My hunch is that the thick black, thick white and copper ground wires should be attached to the matching ceiling wires, and that the other wires are for daisy-chaining to additional matching fixtures. Unfortunately, without a manual it is hard to tell for sure. I would try connecting just those 3 wires and cap (wire-nut) the thin wires for safety (each one separately) and see if that works.


Electric water heater stopped working when I adjusted the thermostat

Electric water heaters are easily repairable if you can get the old heating elements out of the tank.  If they get too corroded, you may not be able to remove them without damaging the tank.

But, that is a bit premature.  You need to test the resistance of the heating elements to determine if they are good.  You can also check that the thermostats are supplying voltage to the elements.  Note that this requires working around live, unshielded 240v connections, so you need to be careful and be sure it matches your comfort level.

The thermostats and elements are pretty standard and you should be able to find replacements at a typical home store.


I have a similar situation, cedar siding that comes down to within a foot or two of the ground, depending on where around the house you are.

I kill the ants, foundation spray, shake pellets. Ants are, for the most part, smarter than I am and will always find a crack or crevice I didn't and they aren't afraid of heights.

I would never seal my siding at the bottom. Depends on different situations, the house is 60ish years old. Well before things were tight and meant to be tight. I don't want to trap moisture in a space that was not built for it and where this house needs to breathe or weep excess moisture. Could be wrong, but there is a reason you don't seal stucco there either, water needs an out (I am North East if location and weather matters to you).


Yes. The white wire is simply there in case the device also required 120 volts. as it sounds like the device is straight 240 volts, the white wire is not needed.  Cap it using a twist-on wire connector, or other approved means.


Washing machine drain into 4" cast waste stack

I think you are going to have more difficulty drilling into the cast iron stack, than routing a new pipe. Follow the route of the stack down with your 2 1/2 pipe, and then feed it into your waste water system, using the correct fitting


Can I install a light between two three-way switches?

If you tap into the existing light box: Yes
There you will have the switched power and neutral.
If you try to tap into the triplex running from one of the switches: NO.
There you will only have the travelers and a power.


There are a wide variety of reasons why this happens ranging from the water meter to air in the lines and water hammer. The easiest way to fix it is to install a cushion tank or expansion tank you have to make sure it's a potable water vision.

Here's an example of onewww.amazon.ca

They are relatively inexpensive but do require some plumbing to install.


Ceiling light won't switch off after replacement

Wire color isn't a certainty, particularly with switched power. You need to be certain of how it was wired before and use the same configuration. Without that, you need to disconnect and use test equipment (non-contact tester, multimeter) to determine the neutral, hot line, which hot goes to the switch, and which hot is switched. A common convention would be black as always hot and red is a switched hot, but you need to test to be sure.

Once you have identified the wires, the light fixture will be connected to the neutral and switched hot. The hot from the line needs to go through the switch to become the switched hot. And neutrals should all be connected together.


Should I replace whole system or just leaky component?

If you check right away you may be able to find the leak with bubble solution, loosing most of a charge in 1 week is a very big leak and should be easy to spot.
I would not count on getting another fill of the R22 for 500$ that you got last time that was a really good price. If you can identify the leak it may be a simple fix so yes 150 may be worth it but remember you will have 500-1000 to top it up. If you can identify a leak with bubble solution I would get it fixed but if you can not find a leak time for a new system.


How can I seal around this pipe on my roof?

Sounds like you should just get the right sized pipe boot rather than trying to glue the wrong sized pieces together.


Option A - Blow it in (if there's no insulation in place between ceiling and floor now.) Drill holes, stuff in hoses (or hire a professional insulation-blowing company who may be better at it that you will be - it's somewhat tricky.)
Option B - rip it open, insulate, re-cover. Consider adding radiant floor heat tubing first.
Option C - add sheet insulation, and more drywall over that. You do NOT want exposed plastic insulation on the ceiling of a garage that's below living space - that would constitute a huge fire hazard.


Pretty much anything is possible, especially in steel, The engineer will tell you how it should be done. In some cases it may make more sense to replace the beam instead of reinforcing it.


Concrete Block Raised Pond - Will it be strong enough?

Not sure what it might be called where you are, but there's a "reinforced stucco" (might be called reinforced render in where you are) that can be used to drystack blocks and then bond them together as a unit - parging a layer of that around the inside would provide some structural benefits. If you can't find the product as a product, you might be able to find loose reinforcing fibers for cementitious products and add them to a render/stucco coat for the same effect. "Surface bonding cement" seems to be another name for it. Third possibility - the render coat you have might already be reinforced?
As to whether or you need to do anything, partly depends on frost movement or lack thereof as a concern - you are correct that it's not very deep, so the pressure is quite low, but unreinforced masonry has very little tensile strength. If the water was not drained and it froze, you can just about guarantee that it will crack, unless you shape it to have tapered sides. Even emptied, movement from frost in the ground will usually crack unreinforced walls. If frost is unheard of in your location, that might be a reason not to bother doing anything. Since you are using a liner, tapering the sides should be as easy as building up sand against the wall before placing the liner.


plastic pipe coming out of wall is really loud

It's a direct-vent (a.k.a. powervent) water heater exhaust. My home has the same thing. The first night I slept there it about knocked me out of bed, and now we usually keep the window closed on that side.

You can find duct mufflers that will dramatically reduce the noise, but they're something you'd need to work with your property owner to install safely and according to building and rental codes. You're dealing with carbon monoxide, so you don't want to take risks.

Another option might be to route the pipe up the wall and above the roofline, or simply to direct the opening away from windows. Again, this would require homeowner approval and assistance, and you need to prevent rainwater intrusion.


How can I securely mount a ceiling lamp where no box exists?

Nik, you need to install a piece of lumber (or some such support member) that is securely attached to joists, that spans the location where you want to attach the fixture. They make some ready-to-install gadgets for this also:


How can I hang a poster on a metallic surface?

If it would work use magnetics. For supper flat use scotch tape, and tape the corners, or you could use poster adhesive strip but that will rase the edges a little.


How can I add a ground wire to my older Square D panel?

No need to add ground wires. There are more serious problems.

In  EMT/IMC/Rigid conduit, the conduit is the ground

This looks exactly like every one of my panels.  No grounds in sight and no ground bar.   And I get the occasional sophomore who goes "How old is this service?" "1960." "Oh noes, there are no ground wires!" "So?" "You need to put ground wires in all these conduits!" "No, you don't."

Presuming the 1978 install date, plastic conduit was not popular at that time.  We know the branch circuits are conduit because you said you plan to add a ground wire.  We know the feeder is conduit because there are other circuits in there.  So I'm gonna bet that most if not all of these are metal conduit, but double check that yourself.

I would speculate you're in Chicago, commercial (e.g. condo or converted space) or somewhere conduit is mandatory.

If it's PVC conduit, then yeah, you need a ground wire.

On to the problems.

1. Grounds on the neutral bar.

I'm guessing this was done by a noob or Romex monkey unfamiliar with wiring methods here, and out of inexperience hucked the green wires onto "the bar, since 99% of what I do is into main panels therefore neutral==ground AFIAC".

Which is wrong, as you observe.  You will need to ground the green wires.  One option is to drill and tap a  #10-32 hole in the service panel back wall, and ground them to that with a pigtail.  Another option is to follow the conduit down to the next junction box.  If the conduit and junction box are all-metal, then one of the holes in the junction box will be tapped #10-32. Stick a little green ground screw in that hole, pigtail off that, and ground there.  That's SOP for me when I make an EMT-Romex transition.  As a result my service panels have no ground wires at all.

Another option is to get a ground bar for that panel.

That noobness is a yellow-flag for other aspects of that work, so I would follow those green wires and carefully inspect all that for compliance with local Codes.

2. Way too many wires in that conduit

There's a rule, 310.15(B)(3)(A), which applies to conduit over 24" long.  It  forces you to derate wires when too many are in a conduit.  For 120/240V split-phase, things factor out to this:

2 or 3 circuits per conduit: No real effects.
4 circuits per conduit:  15-30A circuits unaffected. 2/0 copper limited to 150A.
5-10 circuits per conduit: 15-30A circuits must upsize by -2 numerical sizes. 2/0 copper limited to 100A.

Whatever you've got to do to get down to 4 circuits per conduit, go ahead and do that. Stick with my table above; if you deep-dive into the gory details of 310.15(B)(3)(A) remember neutrals are free in 240V split-phase circuits, and grounds are always free, so every circuit counts as 2 wires.  But "no more than 4" is the rule of the hour.

3. Serving neutrals out of a different panel than hots

Oh heck, no.

Your plan of moving the breakers so the hots and neutral come out of the same panel is just right.

4. Seeing if the N-G bond is pulled

Pretty easy.  Throw as many loads as you can onto circuits in this subpanel.  Then use a DVM to measure voltage between the neutral bar and panel case.  If it's not bonded, you will see a small voltage differential, fraction of a volt.

Now, turn the loads off (right at the breakers is fine).  The voltage differential should get significantly smaller tending to zero.

If it was improperly bonded, the voltage difference would stay very close to zero and not move when you cut loads.

5. All those missing grounds

A similar test can be done on branch circuits to see if they are grounded.  Measure the voltage between N and G at a socket. If the circuit is quiescent, you will see the same difference between N and G that's present at the panel.  Then, plug in a big load like a heater and watch it change. You will see the N-G voltage difference increase just a tick.

I would expect them all to pass; metal conduit is pretty good stuff.

6. 225A subpanel on 2/0 copper wire

130 mph tires on my 90 mph car.  Problem?  No. 130 mph is a "never exceed" rating not a mandate.

This subpanel has no main breaker, so "225A" is the bus rating.  You are not allowed to feed this panel from a 300A breaker.  I rather doubt you are.

What matters is the breaker on the other end of those 2/0 wires, which is what protects the wires and the panel.  I rather suspect it's 100-175A depending on how correctly they followed the conduit-derate rules.  I'm not expecting to find a problem here.

7. Multi-wire branch circuits.  Without handle ties

I see 17 hots landing on breakers, but only 9 neutrals.  There appear to be five cases of black-red pairs landing on individual breakers. Now, mind you, "hot" colors cannot be relied on to be meaningful, but I feel most likely these are multi-wire branch circuits (MWBC).

These two hots seem to be individual circuits, but they share a neutral.  That makes them a single circuit.

Modern MWBC rules absolutely require you to put these either on a handle-tied or 2-pole breaker.  So that when you shut off the circuit for maintenance, both hots shut off.  The two hots must be matched ones sharing the same neutral. They probably were grouped adjacent once, but as breakers get moved around, who knows?

Also, the two MWBC hots must be 240V apart, i.e. on opposite poles.  If they measure 0V apart, that means current from each leg will add, and that will overload the neutral.

8. Wires not identified as relating to each other

I see a glob of black, red and white wires heading off into big pipes.  With no evidence to tell you which hot-neutral or hot-hot-neutral group goes together in which circuits.

That's illegal, for so many reasons. Just you wait, when you start putting GFCI breakers in here, you're going to need to know which neutral goes with which hot.

So I'm afraid you're going to have to get a clamp meter and heater, and make a map, and figure out which neutral(s) return current for which hot(s).  Once they're identified, wrap the groups of wires with tape or shrink tubing.   Since the last guy only used black white red, you might as well get multi-colored tape and color each wire of your MWBCs: the blue group, the green group, the yellow group, the brown group, the orange group, etc.

With THHN wire in conduit smaller than #6, the native color defines hot/neutral/ground: putting colored tape on them does not change their function. Blue tape on a white wire = neutral in blue group.

9. Wires too short to reach every breaker in the panel

Oh wait, you don't have that problem. Don't create that problem.


What is the functional difference between using a ground wire, and grounding to a fixture?

It makes no difference as to method of attaching the safety ground as long as the connection is:

a) Done so that the electrical wiring code is followed

b) The connection is reliable and will remain reliable

c) The reliability of the connection continues years into its service life

In any case most switches, outlets, light fixtures these days have separate safety ground screws or wire pigtails that are meant to be connected with the bare ground wire of the feeder cable in the electrical box.


I have used a combination of construction adhesive and concrete nails. Doing it by drilling and an insert or a concrete screw would be awesome but that is really going to take some time


3 wire service to panel... neutral and ground wires on the same bar?

Whoever told you the meter was the point of disconnect was dead wrong.
The main panel or disconnect is the first means of overcurrent or disconnect. THIS is where your neutral bond must happen.

  2011 NEC

  Article 250 Grounding and Bonding

  II. System Grounding

  250.24 Grounding Service-Supplied Alternating-Current Systems

  (B) Main Bonding Jumper.

  For a grounded system, an unspliced main bonding jumper shall be used
  to connect the equipment grounding conductor(s) and the
  service-disconnect enclosure to the grounded conductor within the
  enclosure for each service disconnect in accordance with 250.28.*


How to rip out inground pool's steel walls?

I'd personally be surprised if they were steel, but a magnet should be handy for verifying that they are not (or are.)

If you are in full destructo-mindset and not going to change your mind over the winter, drilling hole(s) and looking at what comes out of the drilled hole (and what you see looking in the drilled hole) can also be very diagnostic.

If, as seems far more likely to me, the pool is gunite or fiberglass, all you need to do is break up the top rim deep enough that it won't affect future uses (lawn, garden, etc) of that area, and fill it in - unless you are expanding the house into the area.

8 foot deep holes/trenches are distinctly hazardous to be in - if the dirt collapses, it can kill you. Either use digging equipment that keeps you out of the hole, or dig it very wide/sloped.

If it's actually steel, you'll want a 9" angle grinder to make short work of cutting it up, or a 4" if you find a 9" too much to handle. The 9" is faster but requires more effort to control. Investigate tool rental, and get double eye protection (facemask and goggles) and a cheap set of welding leathers so you don't set your clothes on fire. Grinder sparks hurt, and set fires if there's any fuel for them to hide in.


Identifying unspliced pass-through wires in a receptacle box

You don't have to do anything to identify the conductors. However, you'll have to worry about box fill, as these conductors will have to be counted in the fill calculation.

  National Electrical Code 2014

  Chapter 3 Wiring Methods

  Article 314 Outlet, Device, Pull, and Junction Boxes; Conduit Bodies; Fittings, and Handhole Enclosures

  314.16 Number of Conductors in Outlet, Device, and
  Junction Boxes, and Conduit Bodies.

  (B) Box Fill Calculations.

  (1) Conductor Fill. Each conductor that originates outside
  the box and terminates or is spliced within the box shall be
  counted once, and each conductor that passes through the
  box without splice or termination shall be counted once.
  Each loop or coil of unbroken conductor not less than twice
  the minimum length required for free conductors in 300.14
  shall be counted twice. The conductor fill shall be calculated
  using Table 314.16(B). A conductor, no part of which
  leaves the box, shall not be counted.


What could explain a large hole above water heater vent pipe?

It looks pretty obvious to me. Whoever installed the water heater vent intentionally scored the drywall to make a hole for the vent to pass through. I can see the square cut made by a utility knife and they used a hammer to break out the drywall. Then whoever installed the vent did not finish the job by repairing the drywall keeping proper clearances etc.  It is just a sloppy job.


Keeping outdoor deck stair stringers from splitting

I've never had that problem either.  But you could use long screws, say 6". The stringer would be over bored the first 2-3", then piloted for the remaining depth so that only the distal 2" of screw thread into the stringer. The aim is to get the thread to bite into only the solid length of the stringer, not the triangle.  Fill the bore with caulk to keep water out, then drive the screw.

I prefer my screw heads flush or 1/32" proud, never counter sunk.

Alternatively, you could use lengths of angle iron.  The stringer screws would go into the face of the stringer, not the edge. The tread screws would go into the bottom face of the tread (and be hidden). See: https://duckduckgo.com/?q=angle+iron+to+attache+treads+to+stringers&iax=images&ia=images


The "Break Vac" is a vacuum breaker component. You'll find similar devices on sprinkler systems to avoid siphoning water back in should the water supply lose pressure, or on frost free spigots to allow water to drain out of the fixture so it can't freeze and break things. On your washing machine, the design is quite different, simply a plastic funnel sending water into the tub, but the goal is the same, to ensure water can't be siphoned back if there's a loss of water pressure. As for why yours is leaking, you'll need to do some tests to work that out.

If it's high water pressure, you can try partially closing the valves to the washing machine as a quick test, or get a cheap pressure testing gauge to see the water pressure in your home. If it's too high, you may need to have a pressure reducing valve installed where the main enters the home, and possibly an expansion tank to deal with pressure fluctuations from the water heater.

If it's in the wrong position, it should be relatively obvious when you've opened things up. On versions I've been able to find, it clips into place. If the clips are broken, then it's time to replace it. You could perhaps have a problem if the washing machine was significantly out of level.

Two other possibilities that come to mind. You could have a bad clamp holding the hose on to the back of the vacuum breaker, allowing water to leak around that connection. If so, just get a new clamp and replace it. Or there could be too much dirt and debris inside the vacuum breaker throwing off the intended water flow. You can try cleaning it to see if that corrects the issue. If all else fails, I'd just replace the part. It's relatively inexpensive and you appear to be familiar enough with disassembling your machine.


What are the metal parts which are placed against circuit breaker switches used for?

Those are breaker locks. You can hold the breaker in the on position or raise the bar and shut it off holding them in the off position. I can't tell if they are lockable to qualify as a legal lockout device for "maintenance disconnect" purposes.

YES, the breaker WILL still trip even with the lock in place. Trip mechanisms are internal and will work without the handle moving. As soon as the lock is moved the handle would pop into the middle position.

These are used for circuits that people should not be messing with, like alarms, smoke detectors, furnaces, emergency lighting, computers, etc.


How do I install track for sliding closet door on laminate

Laminate flooring is made to move when needed, so screwing through to the subfloor under the laminate may not do the floor well. Since sliding doors do not exert a lot of pressure at the guides on the bottom, you could size the screw to only secure itself into the laminate itself, say no more than 1/2" long screws, considering the laminate should be about 3/8" thick, the mounting plate is about 1/16" thick and the pad under the flooring adds a little too. If the laminate flooring is 1/2" thick, like some are, then a 5/8" screw could be used. Using screws this small should be run in manually, not with a power tool.

To be sure everything moves as it should, you could set the guide completely then remove the screws, file just the sharp point of the screw off, about 1/16", then reset the screws.

Although the floor does move a bit, it should not affect the operation of the guide. If the floor does move enough to do so, more than a 1/2", then you have other issues to worry about.


White Rogers 9600 Thermostat-Set at 70 Deg,dropped to 62 deg-no heat-Trane XR90 gas furnace

There is default programming that somehow probably started running. Maybe somebody pressed "run schedule" or "use schedule" or "run program". If you set the t-stat to "permanent hold" and it still runs the schedule, it's probably a problem with the t-stat itself.
Found this nugget in the install manual for your t-stat. What intrigued me is the default of 62 degrees is what you were experiencing.   The times might be off, install manuals aren't always fully accurate.   EDIT:  just noticed the comment at the bottom of the snippet. 6:00 AM!  Sounds like the default program started running.


Black Greasy Substance inside my Copper Tubing, is it safe

Sounds like you have black sulfur. Unpleasant, but not especially unsafe. You could get a water test and know in more detail what you have in your water.

Anecdotally, I lived in a house that had a very bad case of that for a year or two, carrying in drinking/cooking water, and it was never an issue, though if I was away for a week or two the first flow of water from the pipes was solid black until it flushed itself out. I don't miss living in that house.


How can I prevent heat loss through heater/air conditioner wall units?

You can install an insulating cover on the inside of the unit.  Some vendors caution against using outside covers unless the unit has been cleaned and drained first.


Is it normal for MY lights to briefly dim when my NEIGHBOR is using a power saw?

The dimming lights is caused by voltage dropping.  This could definitely happen from others in your neighbourhood turning on large loads.  Typically anywhere from a few houses to an entire block will share one transformer, so you are pretty much directly sharing the power with them.

If this happens frequently, contact your utility company.  They will be able to check if your neighbourhood needs upgrades to maintain a stable voltage.


Can fill in a doorway opening in a foundation wall over the top of the slab?

I understand the question to be about filling in the foundation wall through the former doorway opening over the top of the floor slab. I would not do so because the slab will have a tendency to move with seasonal soil movement, etc.

Presuming that the slab is poured over a lowered area in the foundation wall, I'd cut back the slab and pour your foundation wall repair directly on the original wall. This will provide the most stability.

If you'd rather not do that, consider simply framing in the opening with wood, using pressure-treated lumber where there's concrete contact. Construction adhesive would secure everything just fine. If it's exposed below the siding on the outside, paint it with an appropriate gray paint to match the foundation. Caulk it in and it'll become nearly invisible.


Your friend is looking for Fish Tape, like this

or like this.


Why is there a live and a neutral in a wall connector?

Hot and neutral are the supply and return lines.  Ground/earth is a safety line and does not normally handle current flow.

What defines a neutral is that some effort has been made to keep it near earth potential.  It is not quite at earth potential** and neutral is not ground.

Now, some plugs and receptacles are polarized, either by virtue of differing pins (the wide blade on NEMA 1), or simply a side effect of having a third grounding pin not inline.  In that case, the appliance knows which pin is neutral, and can be designed internally with that in mind.  The classic example is a screw-in bulb fixture; the easily-touched outer shell of the socket is made neutral, and the harder-to-reach tip is "hot" and also switched.

If its plug is not polarized (Schuko, GU10, GU24), most likely the appliance is required to comply with a higher insulation standard, so the appliance will be nominally safe even if the prongs are reversed.

** and sometimes more than a little not at earth potential


can I put a single mixer tap in a basin that has 3 holes?

Probably.

Will it look good?  Maybe.

Some single hole kitchen faucets have an escutcheon plate that will cover a standard 8 inch,  3 hole to allow you you mount a single hole.


TV mount to 5" door frame instead of stud?

I think you are fine. Predrill the holes because its dry wood. The frame is for sure connected to the studs even if the frame does not connect to the ceiling.