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.
VIEWING DETAILS ABOUT
Thorn EMI Heating
Housewarmer Mk2 30/45extra Efficiency
SAP seasonal efficiency
Rating band
UnknownSpecification
Manufacturer | Thorn EMI Heating Boilers |
Model | Housewarmer Mk230/45extra |
Fuel Type | Gas |
Type | Conventional |
Method | Non-Condensing |
Flue Type | Open |
Fan | No Fan |
Output (kW) | - |
Boiler ID | 4478921 |
Manufactured From/To | Unknown - 1985 |
Summary
The Thorn EMI Heating Housewarmer Mk2 30/45extra is unrated, this probably means it's obsolete or very old.The Housewarmer Mk2 30/45extra is a Non-Condensing Conventional boiler with a maximum power output of kw that uses Gas as its fuel source.
Being an Unrated boiler it would be worthwhile replacing it with a higher efficiency 'A' rated boiler.

Similar Thorn EMI Heating Boilers to the Housewarmer Mk2 30/45extra
(Non-Condensing Gas Conventional)
Results ordered by efficiency. Some models may be obsolete.
72% Efficient
72% Efficient
72% Efficient
72% Efficient
Most Efficient Conventional Gas Boilers
91.3% Efficient
91.3% Efficient
91.3% Efficient
91.3% Efficient
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 Rating | Efficiency | Detached house | Semi-detached house | Mid-terrace house |
---|---|---|---|---|
D | 78 – 82% | £170 | £110 | £100 |
E | 74 – 78% | £190 | £125 | £105 |
F | 70-74% | £220 | £145 | £125 |
G | <70% | £320 | £210 | £180 |
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.