Boiler warranties, and how people lose them
A ten-year warranty is worth a great deal — right up until the moment a missed service turns a covered repair into a bill. Here is what actually keeps one alive.
How long should a warranty be?
It depends entirely on the manufacturer and the model, and to some extent on who fits it. Broadly, mainstream UK boilers come with somewhere between 2 and 12 years of parts-and-labour cover. The longer terms are usually attached to the premium models in a range, and sometimes to installers accredited by that manufacturer.
When we quote a new boiler we tell you the exact warranty term for the model you are choosing, before you commit — and we register it for you once it is in.
The three things that void one
Almost every warranty claim that gets refused comes down to one of these.
1. A missed annual service
This is the big one. Nearly every manufacturer makes the warranty conditional on the boiler being serviced every 12 months by a Gas Safe registered engineer, and on that service being documented. Miss one year and a heat exchanger that would have been free becomes a bill that can run into the hundreds.
Book it in the same month each year so it never slips. Late summer is ideal.
2. A system that was never cleaned
Fit a shiny new boiler onto twenty years of sludge and the sludge goes straight through the new heat exchanger. Manufacturers know this, which is why most require the system to be cleaned to a recognised standard at installation, treated with inhibitor, and in a growing number of cases fitted with a magnetic filter.
If an installer quotes you a new boiler with no mention of flushing, inhibitor or a filter, that quote is cheaper for a reason, and the reason is your warranty.
3. Work by someone unregistered
Any gas work by an engineer who is not Gas Safe registered voids the warranty outright — as well as being illegal and invalidating your home insurance. That includes the annual service.
Keep the paperwork. The Building Regulations compliance certificate from the installation, the warranty registration, and a record of every annual service. If you ever need to claim, the manufacturer will ask for exactly these — and if you sell the house, the buyer's solicitor will too.
What a warranty does not cover
A manufacturer's warranty covers the boiler. It generally does not cover:
- The rest of the system — radiators, pipework, cylinders, thermostats and motorised valves are not the boiler.
- Damage from sludge or limescale, which is treated as a maintenance failure rather than a manufacturing fault.
- Frozen condensate pipes and other weather-related lockouts.
- The annual service itself, which you pay for.
- Poor installation. That is the installer's responsibility, which is why it matters who fits it.
Warranty, guarantee, insurance — not the same thing
- A manufacturer's warranty covers defects in the boiler itself, on their terms, for their term.
- Our workmanship guarantee covers our labour for 12 months. If something we did fails within the year, we come back and put it right at no charge.
- Boiler cover or insurance is a separate monthly product from an insurer or energy supplier. It is not a warranty and does not replace one.
Moving house
Most manufacturer warranties stay with the appliance rather than the owner, so a boiler with warranty left is a genuine selling point — provided the service history is intact. Some require you to notify them of the change of ownership. Check the terms, and hand the folder over with the keys.
Not sure where your boiler stands? We can check the make, model and installation date, tell you what the term should be, and get the service history back on track. Ring 07454 118822 or read about boiler servicing.
Warranty questions
Does a missed service really void my boiler warranty?
In most cases yes. Nearly every manufacturer makes the warranty conditional on an annual service by a Gas Safe registered engineer, documented. A missed year is the single most common reason a claim is refused, so book it in the same month each year.
Who registers the warranty when a new boiler is fitted?
We do. When we install a boiler we notify it under the Building Regulations and register the manufacturer's warranty for you, and you receive the compliance certificate to keep with the house paperwork.
Does the warranty cover my radiators and pipework?
No. A manufacturer's warranty covers the boiler itself. Radiators, pipework, cylinders, thermostats and valves are separate, and damage caused by sludge or limescale in the system is normally excluded as a maintenance issue.
Do I need a magnetic filter for the warranty to stand?
An increasing number of manufacturers require one, and all of them require the system to be cleaned and dosed with inhibitor at installation. A filter is inexpensive, it protects the boiler and it gets emptied at the annual service, so it is worth fitting regardless.
Does the warranty transfer if I sell the house?
Usually yes — most warranties attach to the appliance rather than the owner, provided the service history is intact. Some manufacturers ask to be notified of the change of ownership, so check the terms and pass the paperwork on with the keys.