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.



Xtramax A Efficiency

SAP seasonal efficiency


Rating band

Band D


ManufacturerGlow-worm Boilers
ModelXtramax A
Fuel TypeGas
Flue TypeRoom-Sealed
FanFan Assisted
Output (kW)27.6 - 27.6
Boiler IDGC 47-047-15
Manufactured From/To2001 - current


The Glow-worm Xtramax A is a 'D' rated boiler with an efficiency of 78.9%.

The Xtramax A is a Non-Condensing Combi boiler with a maximum power output of 27.6kw 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 Glow-worm Boilers to the Xtramax A
(Non-Condensing Gas Combi)

Results ordered by efficiency. Some models may be obsolete.

Glow-worm 23c

79.9% Efficient

Glow-worm 30 ci

79.6% Efficient

Glow-worm 30ci Plus

79.6% Efficient

Glow-worm Compact 80e A

79.5% Efficient

Most Efficient Combi Gas Boilers

Alpha CD50

91.2% Efficient