News, Views & Reviews on Domestic Central Heating, Boiler & Renewable Energy


Get Free, No Obligation Boiler Quotes

HRM Boilers Wallstar System 15/20 System 12 Oil - Boiler Efficiency Ratings

Boiler Efficiency Rating

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 0800 327 7119 for a no-obligation quote, alternatively visit Boiler Guide to request quotes from independent local and regional heating engineers.

HRM Boilers Wallstar System 15/20 System 12 Efficiency

SAP seasonal efficiency85.7%
Rating bandBand C


ManufacturerHRM Boilers Boilers
ModelWallstar System 15/20 System 12
Fuel TypeOil
Flue TypeRoom-Sealed
FanFan Assisted
Output (kW)15 - 20
Boiler ID
Manufactured From/To2003 - current


The HRM Boilers Wallstar System 15/20 System 12 is a 'C' rated boiler with an efficiency of 85.7%.

The Wallstar System 15/20 System 12 is a Non-Condensing Conventional boiler with a maximum power output of 20kw 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 HRM Boilers Boilers to the Wallstar System 15/20 System 12
(Non-Condensing Oil Conventional)

Results ordered by efficiency. Some models may be obsolete.

Most Efficient Conventional Oil Boilers