Boiler reviews: Reliability
Every year we survey thousands of Which? members about any problems they've had with their home appliances, to find out which brands are the most reliable. Here we reveal our results by showing you the most reliable boiler brands.
Boiler reliability
Problems with boilers are common - 46% of owners with boilers up to six years old have experienced faults with their gas or oil condensing boilers.
Not all faults require repair, but three in 10 members have had a visit from the boiler engineer.
A frozen condensate pipe, the most frequent problem, has affected 11% of people. Luckily not all faults have needed a repair.
Only logged in Which? members can view full scores in our boiler brand reliability table below. If you're not already a member, you can sign up to try out full access for one month, for just £1.
The most reliable gas boiler brands
Our reliability table reveals the reliability of the brands of gas boiler owned by 85% of the Which? members in our survey who own a gas boiler. All the major brands of gas condensing boilers are covered, including Baxi, Glow-worm, Potterton, Vaillant and Worcester.
Two gas boiler manufacturers have good reliability. The reliability of four manufacturers is average and one manufacturer has below average reliability. Log in to find out which they are.
| Gas boilers Which? reliability index | ||
|---|---|---|
| Boiler | Rating | Score |
| Baxi |  | |
| British Gas | | |
| Glow-worm | | |
| Ideal | | |
| Potterton | | |
| Vaillant | | |
| Worcester | | |
Table notes
The average reliability score is 71%, based on 1,706 responses from people who had bought a condensing gas boiler since 1 April 2005.
Respondents for each brand are: Baxi (132); British Gas (97); Glow-worm (165); Ideal (97); Potterton (96); Vaillant (301); Worcester Bosch (567).
The most reliable oil boiler brands
For the first time we can report on the reliability of two major oil boiler brands, Worcester and Grant, which are the choice of two-thirds of Which? members with oil boilers.
| Oil boilers Which? reliability index | ||
|---|---|---|
| Boiler | Rating | Score |
| Grant | | |
| Worcester | | |
Table notes
The average reliability score is 72%, based on 336 responses from people who had bought a condensing oil boiler since 1 April 2005.
The responses for each brand we have enough responses to report on are: Grant (135); Worcester (118).
Our research
In May and June 2011 we surveyed 5,758 Which? Connect online panel members about the problems that 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
More on boilers...
- Read our top boiler maintenance tips
- Find out how to cut the cost of boiler spares
- Our reviews can help find the best boiler for you
