Boiler Efficiency Ratings

Compare new boilers and assess whether your current boiler would be better off being replaced

Our boiler efficiency tables provided by SEDBUK (the seasonal efficiency of domestic boilers in the UK) provide a guide of how effective your boiler is at turning fuel into heat.

You can check your boilers rating by selecting it’s make and model below. Ratings are based on the SEDBUK Rating which is an indicator of its efficiency when used within an average domestic household, it’s a great benchmark for comparing new boilers and also assessing whether your current boiler would be better off being replaced due to low efficiencies.

For new boiler installations call British Gas Boilers on 0333 230 5216 for a no-obligation quote, alternatively visit Boiler Guide to request quotes from independent local and regional heating engineers.



System 28 Eco Efficiency

SAP seasonal efficiency


Rating band

Band A


ManufacturerMain Boilers
ModelSystem 28 Eco
Fuel TypeGas
Flue TypeRoom-Sealed
FanFan Assisted
Output (kW)28.63 - 28.63
Boiler IDGC No. 41-467-12
Manufactured From/To2008 - 2012


The Main System 28 Eco is an 'A' rated boiler which has an excellent efficiency of 90.2%.

The System 28 Eco is a Condensing Conventional boiler with a maximum power output of 28.63kw that uses Gas as its fuel source.

As this boiler is 'A' rated it will provide efficient heating and subsequently reduce fuel bills and carbon dioxide emissions.


Similar Main Boilers to the System 28 Eco
(Condensing Gas Conventional)

Results ordered by efficiency. Some models may be obsolete.

Main 15 HE A

91.3% Efficient

Main System 24 Eco

91.1% Efficient

Main System Eco Elite 24

91.1% Efficient

Main 24 HE A

90.9% Efficient

Most Efficient Conventional Gas Boilers

Baxi Solo 15 HE A

91.3% Efficient

Main 15 HE A

91.3% Efficient

Potterton Promax SL 15

91.3% Efficient

Potterton Gold H 15

91.3% Efficient