Do you need a boiler service to keep your warranty?

If your boiler is still under its manufacturer's guarantee, the short answer is yes. Most boiler manufacturers make a yearly service by a qualified engineer a condition of the guarantee, and if you skip it, a claim for a breakdown can be turned down or the cover cut back.

This post explains what the guarantee usually asks of you, who is allowed to do the service, what to keep as proof and what to do if a service has slipped. You can check your own paperwork and settings safely at home, but the service itself is a job for a Gas Safe registered engineer, never something to attempt yourself.

Why manufacturers ask for a yearly service

A boiler guarantee (often called a warranty) is the manufacturer's promise to repair or replace faulty parts for a set number of years. Many new boilers come with several years of cover, and some much longer, but that promise comes with conditions.

The main one is servicing. Worcester Bosch states plainly that it is a condition of its guarantee that the boiler is serviced every year. Baxi says the same, and adds that if the conditions are not met, its warranty falls back to the standard one year.

The reasoning is simple. A boiler that is checked and cleaned every year is far less likely to fail, and when it does, the service history shows the fault was not caused by neglect. Without that history, the manufacturer can argue that you did not take reasonable care of it.

Who is allowed to service your boiler

The service must be done by an engineer on the Gas Safe Register, the official list of people legally allowed to work on gas appliances in the UK. Anyone not on the register working on your boiler is breaking the law, and their work will not count towards your guarantee.

Some manufacturers go further. Worcester Bosch recommends that, where possible, the engineer who fitted the boiler services it, or failing that a Worcester Accredited Installer or another Gas Safe registered engineer.

Before anyone starts work, ask to see their Gas Safe ID card. It shows their licence number, the dates their registration runs and the type of gas work they are qualified to do. You can also check the number on the Gas Safe Register website.

Registering the guarantee in the first place

A yearly service only protects a guarantee that has been registered. Cover is not always automatic. Which? advises that most manufacturers need the boiler registering within 30 days of it being fitted, usually online or by phone, and Baxi sets the same 30 day limit.

Many installers register the boiler for you, but it is worth checking rather than assuming. Most manufacturers let you check your guarantee status on their website using the boiler's serial number, which is printed on a label on the boiler or in its manual.

What a service involves

On a service, the engineer checks the boiler is burning gas safely, tests the safety devices, checks the flue (the pipe that carries waste gases outside), checks the pressure and cleans parts that build up deposits. On many systems they will also clean the magnetic filter, a small canister on the pipework that catches sludge before it reaches the boiler. Baxi lists checking the system water for sludge and cleaning the filter as part of the yearly service it expects.

For a fuller walk through each step, see our guide to what's included in a boiler service.

Keeping proof of every service

If you ever need to claim, the manufacturer will ask for proof that the boiler has been serviced each year. Keep these somewhere safe:

• the paperwork or certificate the engineer leaves after each service
• the Benchmark record, a checklist in the back of the boiler's manual (or kept digitally) where the installer and every service engineer record what they did
• the installation paperwork and your guarantee registration confirmation

Which? notes that if your installer set up a digital Benchmark record, the Benchmark app can store your service history and remind you when the next service is due. If you move house, leave these papers for the new owner, as the guarantee usually stays with the boiler.

What a guarantee does and does not cover

Even with every service on time, a guarantee covers faults in the boiler itself, not everything that can go wrong with your heating. Which? points out that some smaller parts, such as fuses and filters, may be left out. Faults caused by sludge in the system, or by work done by someone who is not qualified, may also be excluded.

The terms vary between makes and models, so it is worth reading yours once and noting the service date it expects.

What to do if you have missed a service

Missing a service does not always mean the guarantee is lost, but the longer it is left, the weaker your position. The best step is to book a service as soon as you can, then contact the manufacturer, explain what happened and ask where you stand. Some are more flexible than others.

What you should not do is wait for a fault to appear before booking. A breakdown with no recent service record is exactly the kind of claim most likely to be refused.

Autumn is a good time to get back on track. Booking now means any problem is found before the colder weeks, when engineers are busiest and a breakdown is hardest to live with.

How we keep your guarantee on track

TwinSun Heating's engineers are Gas Safe registered, and we are a Worcester Bosch Accredited Installer, one of the routes Worcester Bosch names for servicing its boilers.

If we have fitted a Worcester boiler for you, our Warranty Booster plan is set up to keep it serviced every year, so the guarantee stays protected. If you would rather not have to remember, our boiler service plans include a yearly service, spread the cost monthly, and we get in touch before your service is due.

If your boiler is due, or you are not sure when it was last done, TwinSun Heating can service it and check your paperwork is in order while we are there. Book a visit through our boiler servicing page and we will arrange a time that suits you.