Boiler Service: What It Costs and What's Included (2026)

A boiler service is a yearly check by a Gas Safe registered engineer that keeps a gas boiler burning safely and efficiently. The engineer takes the casing off, inspects and cleans the parts that wear, tests the flue and measures what comes out of it. In 2026 a one-off gas boiler service usually costs £70 to £150 from an independent engineer, based on Which? and Heatable figures.

Tell us your postcode and we’ll pass your request to Gas Safe registered engineers who cover your area. They contact you directly with their prices and dates.

What a gas boiler service includes

Gas Safe Register describes a service as work carried out to the manufacturer’s instructions to keep an appliance safe and efficient, including cleaning. A full service should cover:

A visual check of the boiler, pipework, flame and casing seals.
The flue, inside and outside. It should be sealed, supported and clear, with the terminal outside unblocked.
A flue gas analysis. A handheld analyser goes into the test point on the flue to measure carbon monoxide and how well the gas is burning.
Gas pressure or heat input, checked against the manufacturer’s figures.
Inside the case. The burner, heat exchanger, injector, ignition and flame sensing probes are checked and cleaned where needed.
Safety devices and controls, so the boiler shuts down when it should and your thermostat and timer work.
System pressure, leaks and corrosion around the boiler.
A written report with the readings taken and anything found.

Our boiler service guide goes through each check in more detail.

How long it takes and how to spot a rushed visit

Which? says a proper service takes at least 30 minutes. Selectra puts a healthy modern combi at 30 to 45 minutes, and longer for an older boiler or one with a fault. Be wary if:

the front cover never came off
no flue gas analyser was used
nobody looked at the flue terminal outside
you were given a tick sheet with no readings, or no paperwork at all
the visit turned into a pitch for a new boiler or a power flush with no evidence of a fault

You’re entitled to ask what the readings were. A good engineer will tell you and explain anything outside the manufacturer’s limits.

How often to service your boiler

Once every 12 months. Which?, Selectra and Heatable all recommend a yearly service. Most manufacturers make an annual service a condition of the warranty, and Which? warns that missing one could invalidate it. Keep every report with your boiler paperwork for warranty claims.

Timing matters for price as well as convenience. Selectra notes engineers’ prices go up from October to February, when breakdowns peak. If you can, book in spring or summer and keep to the same month each year.

Landlords: the gas safety check

If you let a home, the rules are stricter. HSE guidance says you must:

have every gas appliance and flue you provide checked by a Gas Safe registered engineer every 12 months
keep a record of each check for two years
give existing tenants a copy within 28 days of the check, and new tenants a copy before they move in

Since 2018 you can have the check done up to two months early and keep the original renewal date. The gas safety check, often called a CP12, is not a service. Gas Safe Register explains it doesn’t include cleaning. HSE also expects gas appliances to be maintained, and many landlords book the service and safety check on the same visit. Heatable puts the safety check alone at £100 to £150.

Pay as you go or boiler cover?

Cover plans bundle the annual service with repairs for a monthly fee. Which? found people paid an average of £183 a year, with some paying up to £300, and prices often rise after the first year. Its research suggests paying for a yearly service and repairs as needed works out cheaper for most households. The average repair found at a service in its survey was £156.

Cover can suit you if:

a surprise bill of a few hundred pounds would be hard to pay
your boiler is older and has broken down before

Before you sign, read what the plan excludes, what the excess is per claim and how much the price can rise at renewal.

Check the engineer

Only a Gas Safe registered engineer can service a gas boiler. Ask to see the ID card when they arrive and check the back, which lists the work they are qualified to do. It should include gas boilers, or the right category for your appliance. You can also search the engineer or business on the Gas Safe Register website before they visit.

Oil boilers need an OFTEC registered technician instead. See oil boiler servicing.

Before and after the visit

Clear access to the boiler and the flue outside, and put pets in another room.
List any niggles. Pressure that keeps dropping, noises, slow hot water or radiators that stay cold at the top are all worth mentioning. Our boiler pressure guide and radiator bleeding guide cover the ones you can sort yourself.
Ask about flow temperature. Which? suggests asking whether a lower setting would cut your bills. Smart controls can help too; see smart thermostat installation.
Check the report before the engineer leaves, and file it.

If the engineer finds a problem

A service often turns up worn parts. Ask for the fault and the price in writing before agreeing to the work. If the boiler is unsafe, the engineer may turn it off and label it; leave it off until it has been fixed. See boiler repair for typical repair prices.

If you’re told the boiler is near the end of its life, get a second opinion and compare quotes. Our boiler installation page and new boiler cost guide explain what a fair replacement costs.

Typical boiler service prices

Job	Typical UK price	Notes
Gas boiler service, independent engineer	£70 to £150	Which? gives £70 to £110 (average about £79); Heatable gives £90 to £150
Gas boiler service, national firm, one-off	£130 to £200	Selectra
Landlord gas safety check (CP12)	£100 to £150	Heatable, labour; a service on the same visit costs extra
Oil boiler service	£110 to £150	Heatable, labour; must be an OFTEC registered technician
Repair found at a service	About £156	Which? survey average
Boiler cover plan, per year	About £183	Which? average; some paid up to £300

Sources: Which?, Selectra and Heatable boiler service cost guides, 2026. Selectra notes prices rise from October to February, and London and the South East cost more.

Boiler servicing guides

What is included in a boiler service?

Boiler servicing by city

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Scotland

Wales

Northern Ireland

Belfast

Common questions

How much does a boiler service cost?

Usually £70 to £150 from an independent Gas Safe engineer in 2026. Which? puts the average one-off gas service at about £79. National firms charge more for a one-off visit, about £130 to £200 according to Selectra.

How often should a boiler be serviced?

Every 12 months. Which?, Selectra and Heatable all recommend an annual service, and most manufacturers make it a condition of the boiler warranty.

Is a boiler service a legal requirement?

Not for homeowners. Landlords must have a gas safety check done every 12 months by a Gas Safe registered engineer, which is a different job from a service. Homeowners should still book a yearly service for safety and to keep the warranty valid.

How long does a boiler service take?

Which? says at least 30 minutes. Selectra puts a healthy modern combi at 30 to 45 minutes, and an older boiler or one with a fault takes longer.

Is a gas safety certificate the same as a boiler service?

No. A gas safety check tests every gas appliance and flue in the home for safety. Gas Safe Register explains it does not include the cleaning and adjustment a service does. Landlords often book both on one visit and get separate paperwork for each.

Boiler service