Boiler Service Cost UK 2026/27: What You Get for the Money
A one-off annual boiler service in the UK typically costs £80 to £120, with the average around £100 to £110, according to 2026 pricing guides. A Landlord Gas Safety Certificate (CP12) on its own is £60 to £90, and combining a service and certificate in one visit is typically £110 to £150 — cheaper than booking each separately. The service must be done by a Gas Safe registered engineer. Quotes significantly below the average can mean an unregistered engineer or a less thorough job, so always check the Gas Safe Register before booking.
Every year, the same choice: pay someone to look at a boiler that’s working, or gamble on it lasting another winter. Here’s what an annual service actually gets you, what it costs in 2026/27, and where to spot corner-cutting.
What’s included in a standard service
A proper annual service covers around ten checks: a visual inspection of the boiler and the room, checking the flue for leaks and blockages, a gas tightness test, verifying burner pressure and combustion, inspecting the heat exchanger, testing safety devices, checking electrical connections, confirming the system pressure, and cleaning components where needed. The engineer should give you a written report at the end.
What it typically costs
- One-off annual service: £80–£120, averaging £100–£110 across the UK in 2026.
- Landlord Gas Safety Certificate (CP12) alone: £60–£90.
- Service and CP12 combined: £110–£150 (usually cheaper than booking them separately).
- Annual boiler cover plans: from around £10–£25 a month depending on cover level, spreading the cost and adding breakdown protection.
London and the South East usually sit at the top of the range; the rest of the country closer to the middle.
What a service doesn’t cover
Why the price varies so much
A £40 “service” advertised on a leaflet through your door and a £120 service from a Gas Safe registered engineer are different things. Energy Guide UK’s 2026 guide warns that a quote significantly below the regional average can mean an unregistered engineer or a less thorough service. All legal gas work in the UK must be done by an engineer on the Gas Safe Register — the successor to CORGI — and they should carry an ID card you can check.
Check the engineer is Gas Safe registered
- Ask for their ID card. It has their photo, licence number, and the categories of gas work they’re qualified for.
- Check the number online at gassaferegister.co.uk, or by phone, before the work starts.
- Confirm the categories match the job (e.g. “natural gas domestic” for most home boilers).
When you have to have a service
Two situations force the issue:
- Manufacturer warranty. Most modern boiler warranties (5, 7, 10 or more years) require documented annual servicing to remain valid. Miss a year and you’ve lost the warranty on a £3,000 boiler.
- You’re a landlord. Gas Safe Register requires an annual gas safety check on all gas appliances in a rented property, carried out by a Gas Safe registered engineer, with a copy of the Landlord Gas Safety Record given to tenants within 28 days and kept for at least two years (until two further checks have been carried out).
When you don’t strictly have to, but should
If you own your home and the boiler is out of warranty, no law requires you to service it. But an unserviced boiler is more likely to break down in the middle of a cold snap when engineers are booked out for weeks, and it’s more likely to develop a slow leak of the products of combustion — including carbon monoxide — that only shows up when someone gets ill. For £100 or so, it’s cheap peace of mind.
An audible carbon monoxide alarm
Non-negotiable if you have a gas appliance
Sealed 7 or 10-year battery on newer models
Test button
Every home with any fuel-burning appliance should have an audible CO alarm certified to EN 50291. Fit it in the same room as the boiler, at head height, away from the boiler itself and away from windows. Test it monthly, and replace the whole unit after its stated life expires — the sensor has a shelf life even if the battery hasn’t run out.
Good for: any home with a gas or oil boiler, gas hob, wood burner, or open fire; peace of mind that a slow leak won’t go unnoticed.
Less good for: replacing a proper annual service — the alarm only warns you when something’s already gone wrong. Certain older models don’t meet current standards.
Book it in early
Engineers are quietest in late spring and summer. September and October are already busy. Once the first cold snap hits in November, everyone finds a boiler problem at once, and the good local engineers get booked weeks out. Booking in early autumn also means you can spread the cost of any repair work over the winter, rather than facing an emergency call-out fee.
Frequently asked questions
How much is a boiler service in the UK?
Typically £80–£120 for a standard one-off annual service in 2026, with an average of £100–£110. Combined with a Landlord Gas Safety Certificate, expect £110–£150.
Do I legally have to service my boiler every year?
If you own and live in the property, no. If you’re a landlord, yes — Gas Safe Register requires an annual gas safety check on all gas appliances in a rented property. Most manufacturer warranties also require documented annual servicing to remain valid.
Why are some boiler services so cheap?
Energy Guide UK’s 2026 pricing guide warns that quotes significantly below the average can mean an unregistered engineer or a less thorough service. All legal gas work must be done by an engineer on the Gas Safe Register — ask to see and verify their ID.
What’s the difference between a boiler service and a Gas Safety Certificate?
A service is a maintenance check on the boiler alone. A CP12 Landlord Gas Safety Certificate confirms all gas appliances in a rented property are safe. Landlords need the certificate annually; a service is often done at the same time.
Sources
- Energy Guide UK — Boiler service costs 2026
- Gas Safe Register — Landlord gas responsibilities
Related reading: our 10 things to check before turning on your heating, frozen boiler condensate pipe guide and how to bleed a radiator.
Compare current carbon monoxide alarms at Amazon UK.
