Typical boiler service cost in the UK
Most homeowners pay somewhere between £70 and £120 for a one-off gas boiler service. The price depends on where you live, whether you use a national company or a local independent engineer, and whether any extra work is needed. Prices in London and parts of the South East are often higher.
| Service type | Typical UK cost |
|---|---|
| Standard gas boiler service | Typically £70 to £120 |
| Gas boiler service in London | Typically £90 to £150 |
| Landlord gas safety check (CP12) only | Typically £60 to £100 |
| Boiler service and gas safety check together | Typically £90 to £160 |
| Boiler cover plan including an annual service | Typically £10 to £25 a month |
A service price normally covers the inspection and routine checks only. If the engineer finds a worn part, such as a seal or a faulty expansion vessel, replacing it is usually charged separately. Ask for a quote before any extra work goes ahead.
What an annual boiler service includes
The exact checks depend on the boiler and the engineer, but a proper service should normally include:
- checking the boiler is working and asking you about any faults or codes you have seen
- a visual inspection of the boiler, pipework and flue for damage, corrosion or leaks
- checking the flue is correctly fitted, sealed and not blocked
- a flue gas analysis to check the boiler is burning gas safely and efficiently
- checking the gas pressure and gas rate
- removing the casing to inspect and, where needed, clean the burner, heat exchanger and electrodes
- checking seals and gaskets
- checking and cleaning the condensate trap and checking the condensate pipe
- testing the safety devices so the boiler shuts down if something goes wrong
- checking the system pressure and the expansion vessel charge
- recording the service in the Benchmark section of your manual or giving you a service report
A service usually takes around 30 to 60 minutes. Be wary of a visit that takes ten minutes and never involves taking the casing off, as that is not a full service.
At the end of the visit, the engineer should tell you whether they found anything that needs attention. If they find something dangerous, they may need to turn the appliance off and label it as unsafe until it is repaired. This is done to protect your household, so do not ignore it or turn the boiler back on yourself.
Why an annual service matters
Safety
A gas boiler that is not burning properly can produce carbon monoxide, which you cannot see or smell. An annual service checks the combustion and the flue so any problem is found early. You should also have a working carbon monoxide alarm near your boiler and any other gas appliances.
Your manufacturer warranty
Most boiler manufacturers require the boiler to be serviced every year by a Gas Safe registered engineer to keep the warranty valid. If you miss a service and the boiler then fails, the manufacturer may refuse to cover the repair. Keep a record of every service.
Fewer breakdowns
Many faults start small. A partly blocked condensate trap, a weak expansion vessel or a worn seal can be spotted during a service long before they cause a lockout on a cold morning. A service is also a good time to ask about recurring problems such as a frozen condensate pipe or ignition faults like Worcester Bosch EA 227.
Efficiency
A clean, correctly set up boiler burns gas more efficiently than one that has been neglected, which helps keep your bills under control. If the engineer notices that the system water is dirty or full of sludge, they may recommend a system flush or a magnetic filter, and both are priced separately from the service.
Check your engineer is Gas Safe registered
By law, anyone working on a gas boiler in the UK must be on the Gas Safe Register. Before the work starts:
- Ask to see the engineer's Gas Safe ID card. It carries their photo, name, licence number and the business they work for.
- Check the back of the card to confirm they are qualified for the type of work, such as domestic gas boilers.
- If you want extra reassurance, look up the engineer or business on the Gas Safe Register website.
Never let anyone who is not Gas Safe registered work on your boiler. If you smell gas at any time, call the National Gas Emergency Service on 0800 111 999.
Landlords: the gas safety certificate (CP12)
If you rent out a property, you are legally required to have every gas appliance, fitting and flue checked for safety every 12 months by a Gas Safe registered engineer. The record is often called a CP12 or landlord gas safety certificate. You must give a copy to existing tenants within 28 days of the check and to new tenants before they move in.
A gas safety check is not the same as a full service. It confirms the appliances are safe to use, but it does not include the cleaning and maintenance that a service does. Many landlords book both at the same visit, which is usually cheaper than two separate call-outs.
How to prepare for a boiler service
- Clear space around the boiler and make sure the engineer can reach the gas meter.
- Note the make and model of the boiler, which is usually printed on the front.
- Write down any fault codes you have seen, such as low pressure warnings, and anything unusual like noises or leaks. Our guides to a boiler leaking water and low pressure can help you describe the problem.
- Find the user manual and Benchmark checklist if you have them.
- Make sure the gas and electricity are on and you have credit if you use a prepayment meter.
- Keep pets and children away from the work area.
Autumn is a popular time to book, as engineers get very busy once the cold weather arrives. Booking your service in late spring or summer is often easier and gives time to fix any problems before winter.