Boiler warranties explained

The short answer

A boiler warranty is the manufacturer’s promise to repair or replace the boiler if it develops a fault covered by its terms. How long it lasts depends on the manufacturer, the model and how it is registered, so check the terms for the exact boiler on your quote. To keep it valid, three things usually matter: the boiler is registered with the manufacturer shortly after installation, it is serviced every year by a Gas Safe registered engineer, and the Benchmark checklist is filled in at installation and at each service.

Get those right and a warranty can save you the cost of a repair or two. Miss them and a claim can be refused even on a young boiler.

Manufacturer warranty vs installer guarantee

These are two different things, and it helps to know which covers what.

• Manufacturer warranty: covers faults with the boiler itself, such as a failed part. It is provided by the brand, and claims go to them. They usually send their own engineer or authorise a repair.
• Installer guarantee: some installers guarantee their own workmanship, such as the pipework, joints and fittings they installed. It is separate from the manufacturer’s warranty, and its terms are set by the installer.

If a pipe joint the installer made starts to leak, that is a workmanship question for the installer. If the boiler’s fan fails, that is a warranty question for the manufacturer. Ask any installer, in writing, what cover they provide for their own work and for how long.

Registering the warranty

Most manufacturers require the boiler to be registered shortly after it is installed, often within 30 days. If it isn’t, the warranty can be shorter than advertised. Some manufacturers also set conditions for their longer warranties, such as a system filter being fitted. That is why the same boiler can come with different warranty lengths from different installers.

Registration should be done in your name, at the property address. Ask your installer to confirm it has been done and to pass on the confirmation, or check with the manufacturer. When we fit a boiler, we register the warranty for you as part of the boiler replacement. It is one of the things worth checking on every quote.

The annual service

Almost every manufacturer requires the boiler to be serviced every year by a Gas Safe registered engineer for the warranty to stay valid. The service checks the boiler is burning safely and efficiently, cleans parts that collect debris, and catches small faults before they become breakdowns. Each service should be recorded in the service section of the Benchmark checklist.

Book it around the anniversary of the installation and keep the record. If a service is missed, the manufacturer may treat the warranty as void. See boiler servicing for what a service involves.

The Benchmark checklist

Benchmark is the commissioning checklist for a new boiler. The installer fills it in on installation day with the details of the boiler, the gas and combustion readings, the controls fitted, and confirmation that the system was cleaned and treated with inhibitor. It is signed and left with you, and the service record pages are completed at each annual service.

Manufacturers ask for it before honouring a warranty claim. A missing or blank checklist makes a claim harder, so check it has been filled in before the engineer leaves, and keep it with the boiler’s manual.

What can void a boiler warranty

• No annual service, or no record of one in the Benchmark checklist.
• Not registered with the manufacturer within the time it asks for.
• Repairs or changes by someone unqualified. Anyone working on the gas side of the boiler must be Gas Safe registered, and some manufacturers ask for their own engineers to do warranty repairs.
• A poorly prepared system. Manufacturers expect the system to be cleaned and treated with inhibitor to BS 7593. Damage caused by sludge or debris may not be covered.
• Damage from outside causes, such as frost or problems with the water or gas supply. Check the terms for what is excluded.

Read the terms that come with the boiler. They set out what is covered, what isn’t, and what you need to do.

Warranty questions to ask before you buy

The warranty is part of what you are paying for, so it is worth knowing the details before you choose a boiler, not after something goes wrong.

• How long is the warranty on this exact model, and does that depend on anything the installer does?
• Does the manufacturer set conditions, such as a system filter or annual servicing by particular engineers?
• Who registers it, and when will I receive confirmation?
• What does it cover, and what is excluded?
• If I sell the home, does the warranty pass to the new owner?
• Separately, what cover does the installer give for their own work?

A warranty is also different from boiler cover or home emergency insurance, which you pay for each month or year. Those are separate products with their own terms. A new boiler with a manufacturer warranty may not need extra cover for parts the warranty already includes, so check what overlaps before you buy both. Our boiler installation cost page explains how warranty length feeds into the price.

Making a claim

If the boiler develops a fault, contact the manufacturer or your installer, depending on the terms. Have the model, serial number, installation date, Benchmark checklist and service records ready. Don’t let anyone unqualified attempt a repair while you wait. For safe things you can check yourself first, such as the pressure, see our guide on how to repressurise a boiler, or book a boiler repair.