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Boiler Efficiency Ratings

Boiler Energy Efficiency Ratings

The energy efficiency of domestic boilers are rated under the SEDBUK scheme (Seasonal Efficiency of Domestic Boilers in the UK) developed by the Government's Energy Efficiency Best Practice Programme.

The scheme rates gas and oil fired boilers on an A to G energy efficiency scale. An A rating represents a high energy efficiency, whilst a G rating represents the lowest energy efficiency rating. Each rating is accompanied by a percentage relating to the amount of fuel used by the boiler which is turned into heat. 'A' rated boilers represent the most energy efficient boilers on the market and will also provide fuel saving benefits. The scheme enables a buyer to make an informed comparative choice based upon the energy efficiency ratings of boilers available on the market.

The ratings used within the scheme represent the annual average energy efficiency of the boiler, taking into account typical boiler usage patterns, different boiler control methods and seasonal climatic variations within the UK over a year. SEDBUK can be used to estimate average annual fuel costs and is used in SAP calculations.

Building regulations specify that all new or replacement gas or oil fired boilers installed must be condensing boilers with an A or B SEDBUK energy efficiency rating. A non condensing boiler can only be fitted in exceptional circumstances where it would be impractical or too costly to install a condensing boiler. If a non condensing boiler is deemed necessary the professional CORGI (gas boilers) or OFTEC (oil boilers) installer must complete a declaration form to accompany the installation certificate.

Condensing boilers are more energy efficient than non condensing boilers as they recover heat from their flue gases, which would otherwise be lost, by utilising heat from flue gas condensate. As condensing boilers use the fuel they consume more efficiently, carbon dioxide emissions are also reduced. It is anticipated that the revised building regulations, due to be implemented in October 2010, will require all new and replacement boilers to carry a SEDBUK A rating.

SEDBUK Rating sticker