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.


Potterton Myson

Combi 100 Efficiency

SAP seasonal efficiency


Rating band

Band D


ManufacturerPotterton Myson Boilers
ModelCombi 100
Fuel TypeGas
Flue TypeRoom-Sealed
FanFan Assisted
Output (kW)29.0 - 29.0
Boiler IDLRR
Manufactured From/To1999 - 2001


The Potterton Myson Combi 100 is a 'D' rated boiler with an efficiency of 78.8%.

The Combi 100 is a Non-Condensing Combi boiler with a maximum power output of 29.0kw that uses Gas as its fuel source.

Being a 'D' rated boiler it would be worthwhile replacing it with a higher efficiency 'A' rated boiler.


Similar Potterton Myson Boilers to the Combi 100
(Non-Condensing Gas Combi)

Results ordered by efficiency. Some models may be obsolete.

Most Efficient Combi Gas Boilers

Alpha CD50

91.2% Efficient