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.



GCCW 23/28 Ext Efficiency

SAP seasonal efficiency


Rating band

Band B


ManufacturerGrandee Boilers
ModelGCCW 23/28 Ext
Fuel TypeOil
Flue TypeOpen or Room-Sealed
FanNo Fan
Output (kW)23 - 26
Boiler ID
Manufactured From/To2008 - current


The Grandee GCCW 23/28 Ext is a 'B' rated boiler which has good efficiency of 88.6%.

The GCCW 23/28 Ext is a Condensing Combi boiler with a maximum power output of 26kw that uses Oil as its fuel source.

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


Similar Grandee Boilers to the GCCW 23/28 Ext
(Condensing Oil Combi)

Results ordered by efficiency. Some models may be obsolete.

Grandee GCCW 15/22

89.1% Efficient

Grandee GCCW 15/22 Ext

89.1% Efficient

Grandee GCCF 15/23

89.1% Efficient

Grandee GCCW 23/28

88.6% Efficient

Most Efficient Combi Oil Boilers