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.


GAH Heating Products

Thermecon 140/190 Option C/F Efficiency

SAP seasonal efficiency


Rating band

Band C


ManufacturerGAH Heating Products Boilers
ModelThermecon 140/190 Option C/F
Fuel TypeOil
Flue TypeOpen
FanFan Assisted
Output (kW)41 - 55.7
Boiler IDCFO140/190
Manufactured From/To2002 - current


The GAH Heating Products Thermecon 140/190 Option C/F is a 'C' rated boiler with an efficiency of 85.0%.

The Thermecon 140/190 Option C/F is a Non-Condensing Conventional boiler with a maximum power output of 55.7kw that uses Oil 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 GAH Heating Products Boilers to the Thermecon 140/190 Option C/F
(Non-Condensing Oil Conventional)

Results ordered by efficiency. Some models may be obsolete.

Most Efficient Conventional Oil Boilers

Grant Vortex 36

97.0% Efficient