Energy Efficiency Ratings for Boilers
Since September 2015, the EU Energy-related Products Directive has set a new standardised scale for rating the energy efficiency of domestic boilers.
This scale, known as ErP for short, ranges from A+++ for the most efficient boilers to D for the least efficient. A percentage efficiency rating is also issued.
ErP replaces the formerly used scale in the UK known as SEDBUK 2005, which ran from A-G. SEDBUK stands for Seasonal Efficiency of Domestic Boilers UK.
A separate percentage efficiency rating known as SEDBUK 2009 is still in use, and may be consulted alongside the new ErP ratings. Typically, SEDBUK 2009 shows a percentage efficiency a few percentage points beneath the ErP efficiency rating because of how it is calculated. For example, a boiler with a 93% ErP efficiency rating may achieve only 89.6% on SEDBUK 2009.
Since April 2018, under the new Boiler Plus legislation, all new domestic gas boilers that are either sold or manufactured in the UK must achieve an ErP energy efficiency rating of at least 92%. As a result, all models of gas boiler that fell beneath this level have had to be discontinued for sale in the UK in 2018.
When energy efficiency ratings for domestic electrical appliances were first introduced, a scale was set out from A, representing the most efficient class to G, representing the least efficient.
With improvements in design and technology, the most efficient classes for some products have since been further subdivided, so that it is now possible for instance to find A* and even A** and A*** ratings for some washing machines, as well as for refrigerators, freezers and fridge-freezers.
In fact, the efficiency scale for washing machines was completely overhauled in 2010, with D becoming the lowest available class and A*** the highest, whereas for refrigerating appliances, the scale still extends down to G.
Since July 2012, it has been illegal to sell a new refrigerator, freezer or fridge-freezer that does not carry an energy rating of at least A*; but even within these tightened parameters, tests by the Consumers’ Association have found wide differences in running costs between models, ranging from £30 to £115 per year.
Why does my gas oven / microwave oven not have an energy-efficiency rating?
The classes of domestic appliances that require energy-efficiency ratings were limited by EU law, and both gas ovens and microwave ovens have so far been exempted. As a result, there has been no scale of efficiency ratings established for these classes of appliances, and consequently no ratings have been given to any models.