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Boiler Reliability

By Matthew Knight

Find out which is the most reliable boiler brand, or if a Glow-worm boiler will outlast a Baxi. Then pick a reliable boiler using our boiler reviews. 

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Our Test Labs compare features and prices on a range of products. Try Which? to unlock our reviews. You'll instantly be able to compare our test scores, so you can make sure you don't get stuck with a Don't Buy.

We asked more than 10,000 boiler owners about the brand of boiler they own so that we can tell you which are the best and worst boiler brands.

Our unique research enables us to tell you which brands are the most reliable, and which are likely to let you down during the cold winter months. As you can see from our table (below), there's a big difference between the most and least reliable brands.

To find out which brands are best and worst for reliability, Which? members can log in to unlock the table below. Not yet a member? Take out a one-month trial for £1 and get instant access to our boiler reliability results and all of the reviews on our website.

Boiler faults

In our survey we found that problems with boilers are common - 23% of owners with boilers bought since 2010 have experienced faults with their gas or oil condensing boilers. Not all faults require a boiler repair, but three in 10 owners have had a visit from the boiler engineer to fix a fault.

A boiler losing pressure or water leakage are the most frequent problems, having affected 11% and 5% of people, respectively. 

Gas boiler brands rated for reliability
Gas boiler reliability table
Brand Reliability rating


Member Content
Oil boiler reliability
Oil boiler brands rated for reliability
Brand Reliability rating
Worcester Bosch


Member Content

Our research

In May 2016 we surveyed 11,460 Which? members online about the problems they had experienced with their main gas or oil central heating boiler. The reliability score is based on whether people who own boilers up to six years old have ever had to have their main boiler repaired since they bought or acquired it.


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