Radiant - Boiler Efficiency Rating

Compare new boilers and assess whether your current boiler needs to be replaced.

A boiler’s energy rating is an indicator of its efficiency when used within an average domestic household. It’s a great benchmark for comparing new boilers and can help you work out how much money you could save on energy bills if you replaced your current boiler with a more efficient model.

You can find out the energy efficiency of your boiler by checking its energy rating; you can do this now by selecting the make and model below.

How efficient is your boiler?

Select your boiler using the dropdown below to find out.

Radiant Boilers

RadiantB-CondenseRHA 28/100CondensingGas87.2%
RadiantB-CondenseRHA 28CondensingGas86.7%
RadiantB-condenseRH 28CondensingGas86.3%
RadiantB-condenseRHR 28CondensingGas86.2%
RadiantRadiantRK 50CondensingGas90.3%
RadiantRadiantRBS 24Non-CondensingGas79.0%
RadiantRBA CS 30Non-CondensingGas80.8%
RadiantRBA CS 30/100Non-CondensingGas81.1%
RadiantRBA/CS 100 ENon-CondensingGas78.6%
RadiantRBA/CS 24 ENon-CondensingGas78.3%
RadiantRBC 20 ENon-CondensingGas76.7%
RadiantRBS 20 ENon-CondensingGas77.5%
RadiantRBS 20 EMidyNon-CondensingGas79.6%
RadiantRH 25CondensingGas86.3%
RadiantRH 25/BCondensingGas86.3%
RadiantRH 29CondensingGas86.2%
RadiantRH 29/BCondensingGas86.2%
RadiantRH 34CondensingGas86.3%
RadiantRH 34/BCondensingGas86.3%
RadiantRHA 25CondensingGas86.7%
RadiantRHA 25/100CondensingGas87.2%
RadiantRHA 29CondensingGas86.6%
RadiantRHA 29/100CondensingGas87.1%
RadiantRHA 34CondensingGas86.7%
RadiantRHA 34/100CondensingGas87.2%
RadiantRHR 25CondensingGas86.2%
RadiantRHR 29CondensingGas86.1%
RadiantRHR 34CondensingGas86.2%
RadiantRK 18CondensingGas90.5%
RadiantRK 18/BCondensingGas90.5%
RadiantRK 25CondensingGas90.2%
RadiantRK 29CondensingGas90.4%
RadiantRK 29/BCondensingGas90.4%
RadiantRK 34CondensingGas90.5%
RadiantRK 34/BCondensingGas90.5%
RadiantRKA 100CondensingGas91.1%
RadiantRKA 18CondensingGas90.9%
RadiantRKA 18/100CondensingGas91.4%
RadiantRKA 18/8CondensingGas90.4%
RadiantRKA 25CondensingGas90.7%
RadiantRKA 25/100CondensingGas91.1%
RadiantRKA 25/8CondensingGas90.1%
RadiantRKA 29CondensingGas90.8%
RadiantRKA 29/100CondensingGas91.3%
RadiantRKA 34CondensingGas90.9%
RadiantRKA 34/100CondensingGas91.4%
RadiantRKR 18CondensingGas90.4%
RadiantRKR 25CondensingGas90.1%
RadiantRKR 29CondensingGas90.3%
RadiantRKR 34CondensingGas90.4%
RadiantRMAS 20Non-CondensingGas79.1%
RadiantRMAS 21 E NOxNon-CondensingGas80.3%
RadiantRMAS 21 E/3SNon-CondensingGas80.9%
RadiantRMAS 24 ENon-CondensingGas78.1%
RadiantRMAS 30 ENon-CondensingGas80.7%
RadiantRS 20 ENon-CondensingGas78.5%
RadiantRS 21 E NOxNon-CondensingGas79.8%
RadiantRS 21 E/3SNon-CondensingGas80.4%
RadiantRS 24 ENon-CondensingGas77.7%
RadiantRS 24 EMidyNon-CondensingGas79.4%
RadiantRS 30 ENon-CondensingGas80.2%
RadiantRSF 20 ENon-CondensingGas78.4%
RadiantRSF 21 E NOxNon-CondensingGas79.7%
RadiantRSF 21 E/3SNon-CondensingGas80.3%
RadiantRSF 24 ENon-CondensingGas77.6%
RadiantRSF 24 ESlimNon-CondensingGas79.3%
RadiantRSF 30 ENon-CondensingGas80.1%

What are SEDBUK Efficiency Ratings?

From 1999 to 2015 boilers were ranked on the SEDBUK scale which stands for ‘Seasonal Efficiency of a Domestic Boiler in the UK’. While many still refer to SEDBUK as the standard energy rating scale, it was actually replaced in 2015 by the Energy related Products directive, or ErP. It’s directly related to the EU’s ambition to improve the energy efficiency of our homes and achieve the following targets by 2020:

  • 20% reduction in EU greenhouse gas emissions (compared to 1990 levels)
  • 20% improvement in overall energy efficiency (across the EU)
  • 20% more energy produced from renewable resources such as solar or biomass.

Under the current ErP standards, boiler manufacturers are required to label their products with a rating from A++ to G, with G being the least efficient a boiler can be. In September 2019, efficiency grade A+++ will be added and the least efficient class, G, will be removed as an option, removing these products from the market as a result.

How Much Money Could I Save with a More Efficient Boiler

To understand how a new boiler could save you money, you need to consider the energy that an inefficient boiler is wasting. For example, if a boiler is only 70% efficient, for every £1 you spend on heating your home, 30p is being wasted on lost energy. If your new boiler can reach efficiency of 90%, that is just 10p lost of every £1. So that’s a saving of 20p in every £1 which really adds up over time.

The financial savings you could make by replacing your boiler with a more efficient model can be significant, but will vary depending on the size of your home, the fuel used by the boiler and the inefficiency of your existing boiler.

According to the Energy Saving Trust: “Replacing an old gas boiler with a programmer and room thermostat, with a new A-rated condensing boiler with a programmer, room thermostat and thermostatic radiator controls (TRVs) could save you:

Old Boiler ErP RatingEfficiencyDetached houseSemi-detached houseMid-terrace house
D78 – 82%£170£110£100
E74 – 78%£190£125£105

Figures taken from the latest research by the Energy Saving Trust. Based on fuel prices as of April 2017.

For new boiler installations visit Boiler Guide to request quotes from independent local and regional heating engineers.