Boiler warranty explained: what is covered and what voids it

A boiler warranty is the manufacturer’s promise to repair or replace faulty parts on your boiler for a set number of years, at no cost to you. It only holds if the boiler was registered after it was fitted, serviced every year by a Gas Safe registered engineer, and not damaged by something outside the maker’s control. Your installer’s workmanship guarantee is separate, and covers the installation itself.

At Green PHS we offer “Up to 15 years warranty on boilers”, with the exact length depending on the boiler you choose. Here is how boiler warranties work, and how to make sure yours pays out when you need it.

Manufacturer warranty vs installer workmanship

There are usually two separate kinds of cover on a new boiler.

	Manufacturer warranty	Installer workmanship guarantee
Who provides it	The boiler maker	The company that fitted it
What it covers	Faulty parts and manufacturing defects in the boiler	Problems caused by how it was installed, such as a leaking joint
How long	Varies by boiler model and maker	Set by the installer, so ask
How to claim	Call the manufacturer, who usually sends their own engineer	Call your installer

The manufacturer warranty is the big one. It covers the expensive parts: the heat exchanger, the circuit board, the fan, the gas valve. The length varies a lot between brands and between models from the same brand, and sometimes depends on the installer being approved by that manufacturer.

That is why we say “Up to 15 years warranty on boilers”. The exact length depends on the boiler you choose, and we tell you what applies to each option when we give you a free written quote.

What a boiler warranty usually covers

Most manufacturer warranties cover:

• Parts that fail because of a manufacturing fault
• The labour to replace those parts, when done by the manufacturer’s own engineers or approved agents
• In some cases, a replacement boiler if the fault cannot be repaired

They usually do not cover:

• Problems with the rest of your heating system, such as radiators, pipework, valves or controls not made by the boiler maker
• Routine maintenance, including the annual service
• Damage caused by sludge, limescale, frost or a power surge
• Topping up pressure, bleeding radiators or resetting the boiler
• Faults caused by someone who is not Gas Safe registered working on the boiler

Every manufacturer’s terms are different, so read your warranty document. If you have lost it, the terms are usually on the manufacturer’s website.

How to register your boiler warranty

A boiler warranty does not start automatically. It has to be registered with the manufacturer, usually within a set number of days of installation. Many installers do this for you, and we do it for every boiler we fit.

When your new boiler goes in, you should also receive:

1. The Benchmark checklist. This is filled in by the installer at the back of the boiler manual, recording how the boiler was commissioned. Each service is then logged in the same section.
2. A Building Regulations Compliance Certificate. Gas Safe registered installers notify the installation, and the certificate is posted to you afterwards. Keep it with your house documents. You will need it if you sell.
3. Confirmation of the warranty registration, from the manufacturer by email or post.

If you have not had warranty confirmation within a few weeks of the install, contact the installer or the manufacturer to check.

The annual service condition

Almost every manufacturer makes an annual service a condition of the warranty. That means a service roughly every 12 months, carried out by a Gas Safe registered engineer and recorded in the Benchmark section of your boiler manual or on the manufacturer’s online system.

Miss a service, and the manufacturer can refuse a claim. Some allow a short grace period, others do not. Set a reminder each year around the install date. Our guide to how often you should service your boiler explains why the yearly visit matters beyond the warranty, and you can book one through our boiler servicing page.

What voids a boiler warranty?

These are the most common reasons a claim gets turned down:

• No annual service, or a service not recorded properly
• Work by someone who is not Gas Safe registered. Any gas work on your boiler must be done by a registered engineer. You can check an engineer’s registration on the Gas Safe Register website
• No system clean or inhibitor at installation. Manufacturers expect the heating system to be cleaned and treated when the boiler goes in. Our guide to the magnetic boiler filter explains why sludge protection matters
• No filter where one was required. Some longer warranties depend on a magnetic filter being fitted
• Limescale damage. London has hard water, and some manufacturers require a scale reducer to be fitted in hard water areas
• Frost or weather damage, such as a frozen condensate pipe left to cause further damage
• The boiler was never registered

How to claim on your boiler warranty

If your boiler breaks down while under warranty:

1. Check the basics first: the pressure, the power supply and whether a simple reset clears the fault.
2. Find your warranty details and your service records.
3. Call the manufacturer’s helpline and quote the boiler’s serial number, which is on a label on the boiler or in the manual.
4. They will usually book their own engineer to visit.

If you are not sure whether the fault is a boiler part or something else in your heating system, Lee is happy to talk it through on the phone first, so you know who to call.

Is a longer warranty worth paying more for?

A longer boiler warranty is reassuring, but it is not the only thing to compare. The boiler model, its size for your home, the quality of the installation and how well the system is cleaned all matter as much. Our guide on professional boiler installation explains why the fit itself makes such a difference.

When to call an engineer

• Your boiler is under warranty and showing a fault code that a reset does not clear
• You are due a service to keep the warranty valid
• You are not sure whether your boiler was ever registered
• You are choosing a new boiler and want to compare warranty lengths

Call Lee on 020 8050 5913 to talk through warranty options before you choose a boiler, or ask for a free written quote through our boiler installation page. We are Gas Safe registered (no. 617872) and fully insured.