Energy efficiency refers to the amount of energy used to heat your home. An efficient boiler will use less energy to heat your home, which is very cost-effective. Less efficient boilers will require more energy to heat your home, which will cost you more.

What causes a boiler to be inefficient?

Naturally, boilers will never be 100% efficient as some heat is lost through hot gas through the flue. In addition to this, boilers will naturally become less efficient the older they get, which can often be a reason to purchase a new boiler.

Older models of boilers are often less efficient as they are often not built as condensing boilers. Condensing boilers are one of the best types of boilers for efficiency due to condensing vapour, which preserves more energy.

Energy ratings

In the UK, there are two types of energy ratings you may encounter: ErP and SEDBUK. Depending on the age and where the boiler was manufactured will affect which energy rating you encounter.


Energy-related Products (ErP) are a measurement used by the European Union to measure the efficiency of water heating systems, including boilers. The ErP scale ranges from A – G, with A being the most efficient and G being the least. A-rated boilers are at least 90% efficient, while G rated boilers are less than 70% efficient.


Seasonal Efficiency of a Domestic Boiler (SEDBUK) is a measurement used in the UK to determine the efficiency of a boiler made in the UK. There are two versions of the SEDBUK, the 2005 version is a scale from A – G, with the 2009 version replacing the A – G grading with percentages. Since 2015, both of these versions have stopped being used; they have now been replaced with the ErP measurement.


There are variety of benefits to getting a more efficient boiler, including:
-Reduced bills: As the boiler is more efficient, this means less energy is required to heat the home. This consequently decreases the bills.
-Carbon footprint: Due to less energy being required to heat your home, this improves the carbon footprint of your home.

How to maintain efficiency

Over time, a boiler’s efficiency will decrease due to ageing. To maintain the efficiency and reduce the decline, you should:
Service your boiler – Boilers should be serviced annually to check for faults and potential issues. By regularly servicing your boiler, you can avoid any faults that may affect how efficient the boiler is.
-Bleed your radiators when needed: From time to time, your radiators may need bleeding to improve the efficiency of the boiler. If your radiators take a while to heat up or have cold spots, you should bleed your radiators.
-Test your heating monthly: Even in summer, you should test your heating monthly for a few minutes to make sure it is still working with no issues. This is especially important as it will allow you to check for faults when waiting for the next service.

If you have any questions or would like to replace your current boiler with a more efficient boiler, contact us today at or at 01274 317169.