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Boiler warranties: what actually voids them
10 years sounds great until you read the conditions. The three things that void most warranties, and how to keep yours alive.
24 May 2026 · 4 min read
A 10-year warranty is one of the main reasons people pay more for a premium boiler. It's worth having. It's also conditional in ways most people never read.
The three things that void it
No annual service. This is the big one. Miss a single year and most manufacturers will refuse a claim, no matter how minor the fault.
No magnetic filter. Many warranties now require one fitted at installation. If it wasn't on your quote, that warranty may already be worthless.
Not registered. The boiler has to be registered with the manufacturer within a set window, usually 30 days. That's your installer's job, but it's your problem if they don't do it.
What the service actually costs
About £80 to £120 a year. Over ten years, that's £1,000 of servicing protecting a £2,500 boiler and a warranty worth roughly the same.
Which means a 10-year warranty is really a 10-year warranty plus £1,000. Factor that in when you're comparing a boiler with a 5-year warranty against one with 12.
Parts and labour, or just parts?
Read this bit. Some warranties cover parts only, and you pay the engineer's call-out and labour. Others cover both. The difference on a single visit is about £200.
Ask the installer which one you're getting, and get the answer in writing on the quote.
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