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.



Concord CXC48 Efficiency

SAP seasonal efficiency


Rating band

Band C


ManufacturerIdeal Boilers
ModelConcord CXC48
Fuel TypeGas
Flue TypeOpen
FanFan Assisted
Output (kW)48.83 - 48.83
Boiler IDP.I.No 87/AQ/340
Manufactured From/ToUnknown - current


The Ideal Concord CXC48 is a 'C' rated boiler with an efficiency of 85.8%.

The Concord CXC48 is a Condensing Conventional boiler with a maximum power output of 48.83kw that uses Gas as its fuel source.

Although a 'C' rated boiler is not as efficient as many other modern boilers it's still pretty good, only a marginal reduction in fuel bills and carbon dioxide emissions would be observed by replacing it.


Similar Ideal Boilers to the Concord CXC48
(Condensing Gas Conventional)

Results ordered by efficiency. Some models may be obsolete.

Ideal Logic + Heat 12

91.2% Efficient

Ideal Logic Heat 12

91.2% Efficient

Ideal Vogue s18

91.1% Efficient

Ideal Vogue s32

91.1% 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