The short answer
A new gas boiler usually comes with a manufacturer warranty of 2 to 10 years, and some models offer up to 12. The warranty pays for repairs to faults in the boiler itself, usually including parts and labour. To keep it valid you normally need to register the boiler with the manufacturer soon after fitting, get it serviced every year by a Gas Safe registered engineer, and keep the paperwork. Longer warranties often come with extra conditions, such as an approved installer and a magnetic filter. The warranty is only as good as your record of meeting those conditions.
Typical warranty lengths
| Warranty length | Where you usually see it |
|---|---|
| 2 to 3 years | Entry level boilers, or standard terms where extended conditions are not met |
| 5 to 7 years | Mid range models, often with installer registration |
| 10 years | Premium models, usually through an approved installer |
| Up to 12 years | Some top models, with the strictest conditions |
The same boiler can carry different warranty lengths depending on who fits it. A manufacturer may offer a longer term only when the installer belongs to its approved scheme, or when the boiler is fitted with a particular filter or control. Your quote should state the exact warranty you will get, not the “up to” figure from the brochure.
A longer warranty usually means a pricier boiler. On a typical combi swap of £2,200 to £3,400 fitted (national range, checked October 2026), the warranty length is one of the main things that moves the price.
What a warranty covers
Most manufacturer warranties cover:
- faults in the boiler caused by faulty parts or manufacture
- the replacement part and the engineer’s labour to fit it
- callouts by the manufacturer’s own engineers or appointed agents
They usually do not cover:
- Sludge and debris damage. Blocked heat exchangers or pumps caused by dirty system water.
- Limescale. Damage in hard water areas where no scale protection was fitted.
- Frost damage, including a frozen condensate pipe.
- Faults outside the boiler. Radiators, valves, pipework, cylinders and most third party controls.
- Poor installation, which is a matter for the installer rather than the manufacturer.
- Accidental damage or tampering.
The conditions that catch people out
- Registration deadline. Most manufacturers ask for the boiler to be registered within a set period after installation, commonly around 30 days. Miss it and you may drop to the basic term.
- Annual servicing. Usually every 12 months, by a Gas Safe registered engineer, and recorded in the service record in the Benchmark checklist at the back of the manual. A missed or late year can be grounds to refuse a claim.
- Water treatment. Many warranties require the system to be cleaned and treated with inhibitor at installation, and a magnetic filter to be fitted.
- Approved installer. Extended terms may only apply if the installer is on the manufacturer’s scheme.
- Change of owner. Some warranties transfer to a new owner when you sell the house, some need re-registering, and some do not transfer. Check if you are moving.
Keep one folder with the installation invoice, the warranty confirmation, the Building Regulations certificate and every service record. If you ever need to claim, that folder is the claim.
Manufacturer warranty, installer guarantee and insurance
These three are different things, and quotes sometimes blur them.
- Manufacturer warranty. Covers the boiler. Provided by the boiler maker.
- Installer guarantee. Covers the installer’s own workmanship, such as leaking joints or a badly routed flue. Ask how long it lasts and what it covers.
- Boiler cover or insurance. A separate paid policy, usually monthly, that may cover breakdowns and parts of the system the warranty does not. It is optional. While your boiler is under a long manufacturer warranty, check carefully what extra you would be paying for.
Questions to ask before you sign
- How many years of manufacturer warranty will I get with this installation, in writing?
- Who registers it, and when will I get confirmation?
- Is a magnetic filter and system flush included?
- What does your own workmanship guarantee cover, and for how long?
- What does a yearly service cost, and do you offer it?
Annual servicing typically costs £80 to £120 (national range, checked October 2026). Over a ten year warranty that is a real cost, so build it into your comparison when one quote offers a longer warranty than another.
How warranties fit the bigger picture
A long warranty is a good sign, but it does not make a boiler the right one for your home. Start with the type and size: see combi vs system vs conventional boilers and what size boiler do I need?. Then compare like-for-like quotes using our boiler replacement cost guide.
Every boiler installer City Boiler connects you with is Gas Safe registered, and their quotes name the boiler model and warranty term so you can compare them properly. Find out more on the boiler replacement hub.
Common questions
How long is a typical boiler warranty?
Manufacturer warranties on new gas boilers usually run from 2 to 10 years, and some models offer up to 12. The longer terms often depend on the boiler being fitted by an installer the manufacturer approves, with a magnetic filter, and registered within a set time.
Does a boiler warranty cover everything?
No. It covers faults in the boiler caused by defective parts or manufacture. It usually excludes damage from sludge, scale, frost, poor installation, or problems elsewhere in the heating system such as radiators, valves and pipework.
Do I have to get my boiler serviced every year for the warranty?
Almost always, yes. Manufacturers usually require an annual service by a Gas Safe registered engineer, recorded in the service section of the Benchmark checklist. Miss one and the manufacturer can refuse a claim.
Who registers the warranty, me or the installer?
Often the installer does it on your behalf, but you should not assume. Ask on installation day, and check you receive a confirmation from the manufacturer. If you have not seen one within a few weeks, register it yourself or chase the installer.