Boiler efficiency ratings aren't necessarily the best guide to boiler efficiency as they don't include all the factors that contribute to gas use.
You may or may not be interested in greener performance; you are almost certainly interested in saving money on your gas and water bills.
It's a fact that since 2005 the majority of new boiler installations have been condensing boilers which are far more efficient than older boilers.
You 'll find boiler efficiency ratings for boiler manufacturers at the Home Heating Guide website.
However, even 'A' rated boilers do not generate maximum boiler efficiency as they lose energy in the form of heat via the flue. You may have noticed excessive 'pluming', that resembles steam, even after someone has a brand new boiler installed.
It could be that GasSaver would be a good investment for you depending on your daily or seasonal energy needs. GasSaver enables households to capture wasted heat and use it for hot water production.
GasSaver has been shown in independent tests to deliver up to 97%+ boiler efficiency and to reduce the energy required for hot water production by 37%. You'll also save up to 7% on your water bill and enjoy hot water running faster to your taps.