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Do I need a boiler service to keep my guarantee?
Almost certainly, yes. There’s no law saying a homeowner has to service a boiler, but nearly every manufacturer’s guarantee depends on a service every year by a Gas Safe registered engineer.
- 12months between services
- 30days to register a new boiler, with most makers
- 12years, our longest Worcester Bosch guarantee
12months between services
A new boiler often comes with a guarantee of seven, ten or even twelve years. It’s one of the best things about buying one. But that guarantee nearly always comes with conditions, and the one that catches people out is the annual service.
Miss it, and the manufacturer can refuse a claim when something goes wrong. That can turn a free repair into a bill for parts and labour.
Here’s what the main makers ask for, and how to make sure you’re covered.
What the guarantee asks for
Two things, nearly every time.
Register it
Most makers want the boiler registered within 30 days of fitting. Ideal, Vaillant and Baxi all say so, and if it’s late the guarantee can drop to a year or two. When we fit a Worcester Bosch, we register it for you.
Service it every year
Worcester Bosch is clear that yearly servicing is a condition of its guarantee, and that it must be done by a Gas Safe registered engineer. Vaillant says the same, and wants the service recorded in the Benchmark section of the boiler manual.
Look after the water
Damage caused by sludge is usually excluded. Some guarantees, including the Baxi 800’s 10 year warranty, depend on a magnetic filter being fitted and kept clean. Your annual service is when that gets checked.
Service record
What the main makers say
| Register within | Annual service | Also worth knowing | |
|---|---|---|---|
| Worcester Bosch | Registered by the installer | A condition of the guarantee, by a Gas Safe engineer | Up to 12 years when fitted by an accredited installer with a filter |
| Vaillant | 30 days, or it drops to 12 months | Yes, recorded in the Benchmark logbook | Water must be kept treated |
| Baxi | 30 days, or it drops to 2 years | Yes, arranged by you | Sludge damage isn’t covered |
| Ideal | 30 days, or it may drop to 12 months | Check your warranty terms | Full terms are in the warranty document |
From each maker’s published guarantee pages, checked 1 November 2026. Terms change, so always check the documents that came with your boiler.
What if I’ve missed a year?
Book one when you can, then check where you stand.
Book a service now. Then check your guarantee terms, or call the manufacturer, to find out where you stand. Some are stricter than others, and it’s better to know before anything goes wrong.
The easiest way to never miss one is to have it booked for you. Every Home Care plan includes your annual service, and your next one is booked automatically each year.
Or from £11 a month on Home Care.
Annual service
Which one sounds like you?
- New boiler, under guaranteeBook its first service
Within 12 months of it being fitted.
- Never remember when it’s dueHome Care Service
Booked for you every year, £11 a month.
- Not sure it was registeredCheck with the maker
Ask us and we’ll tell you how.
- Out of guaranteeStill worth servicing
For safety and to catch faults early.
Common questions
Is a boiler service a legal requirement?
Not for homeowners. Landlords are different: they must have a gas safety check every year by law. For everyone else, the service is a condition of the guarantee rather than the law.
Does the company that fitted my boiler have to service it?
No. Any Gas Safe registered engineer can service a gas boiler for the guarantee. Make sure you get a written report and the service record is filled in.
Does the guarantee pay for the service?
No. The guarantee covers faults with the boiler. The annual service is paid for by you, either as a one-off or as part of a plan.
What counts as a service for the guarantee?
A service carried out once a year by a Gas Safe registered engineer, following the manufacturer’s instructions, with a record of what was done. A quick safety check on its own isn’t the same thing.
Will Home Care keep my guarantee valid?
Yes. Every Home Care plan includes your annual boiler service, booked automatically each year, which is what the guarantee needs.
Can a boiler guarantee be passed on if I sell?
Most stay with the boiler, but terms vary. Our guide on replacing a boiler before selling covers what buyers ask for.
Related pages
Sources: Worcester Bosch, guarantee service; Vaillant, domestic boiler guarantee; Baxi, registering your warranty; Ideal, boiler warranties guide. Checked 1 November 2026.
Not sure what you need? Give us a shout.
Book online in a couple of minutes or give the office a call, Mon to Fri, 9am to 5pm. We’ll tell you what we think, and if the answer is to leave things as they are, we’ll say that too.
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Guarantees of up to 12 years on the boilers we fit. Gas Safe registered. Fife Trusted Trader. 400+ customer reviews.