What a boiler service actually costs
A standard boiler service in the UK typically runs from around £60 to £120 for a single gas boiler, with oil boiler services often sitting a little higher, roughly £80 to £150, because there's more to strip down and clean. These are typical national figures rather than a quote for any specific job — the engineer in front of you, the age of your boiler, and how easy it is to access will all move the number.
Rural areas can push prices toward the top of that range simply because of travel time. An engineer coming out to Combe Martin or Lynton is spending longer on the road than one working a tight patch of Barnstaple streets, and that time has to be accounted for somewhere. It's worth asking whether a callout charge is separate from the service fee, since some firms bundle them and others don't.
If you've got a service plan or cover policy through your energy supplier, the annual service might already be included. Check what you're paying for before booking a one-off visit — it's a surprisingly common way people end up paying twice for the same thing.
What's included in a standard service
A proper service isn't just a five-minute glance at the boiler casing. An engineer working to Gas Safe or manufacturer standards should be:
- Removing the casing and checking the burner, heat exchanger, and main components for wear or damage
- Checking the flue for correct operation and testing for gas leaks
- Measuring flue gas readings to confirm the boiler is burning efficiently and safely
- Checking the pressure, condensate pipe, and any safety devices
- Testing that the boiler fires up, runs, and shuts down as it should
At the end of it, you should get some form of written record — a service report, a sticker inside the casing, or both — noting the date and what was checked. Keep this. It matters for warranty claims and it matters if you ever sell the house.
If an engineer is in and out in ten minutes with no paperwork, that's not really a service. Ask what was checked before they leave, not after.
Boiler service vs CP12 — they're not the same thing
This trips people up constantly, particularly anyone who's just become a landlord or bought their first rental property. A boiler service is a maintenance check — it's about keeping the appliance running well and catching problems early. A CP12, more properly called a Landlord Gas Safety Record, is a legal safety check that any landlord letting a property with gas appliances must have carried out annually by a Gas Safe registered engineer.
The two can be done in the same visit, and often are, but they're not interchangeable. A service doesn't satisfy the legal requirement for a CP12, and a CP12 check on its own isn't the same depth of maintenance as a full service. If you're a landlord in North Devon, it's worth booking both together each year rather than assuming one covers the other — see our landlord gas safety certificate guide for what the CP12 check actually involves and how to book one.
When to book
Once a year is the standard advice, and there's a reason it hasn't changed: most manufacturer warranties are conditional on an annual service, and skipping a year can void cover on a boiler that's only a few years old. Autumn — September through November — is the obvious window, because it's before the coldest snap and before every engineer in the county gets booked solid.
That said, the actual month matters less than not letting a year slip past unnoticed. If your last service was in March, book the next one for around March, not "sometime before winter" — a boiler running 15 months between checks isn't running to warranty terms even if nothing's gone wrong yet.
If your boiler is coming up to its first winter, or you've just moved into a house and don't know its service history, get it checked sooner rather than later. A first service on an unknown boiler often turns up things a previous owner never mentioned.
Gas vs oil — different costs, different rules
Oil boilers cost more to service partly because there's simply more involved: the nozzle, fuel filter, and fuel line all need attention, and the burner unit tends to need more thorough cleaning than a gas equivalent. It's also worth knowing that oil boiler engineers are certified through OFTEC, not Gas Safe — the two schemes cover different fuels and an engineer needs the right one for your boiler type. Our oil boiler services page covers what an oil service involves and what OFTEC certification actually means in practice.
For gas boilers, any engineer doing safety-critical work must be Gas Safe registered — it's a legal requirement, not just good practice. You can find engineers offering this work through our boiler servicing page, and it's always worth checking a registration number against the Gas Safe Register before anyone touches your gas appliances.
The honest answer
If you want a single figure to plan around: budget somewhere in the £60–£150 range for an annual service depending on fuel type and location, expect it to take an hour or so, and expect a written record at the end. Anything that deviates a long way from that — either a suspiciously cheap five-minute job or a bill that's crept up without explanation — is worth a second question before you pay.
Getting more than one quote
It's worth ringing two or three local engineers before booking, not because the market is full of rip-offs, but because service pricing genuinely varies by business size, overheads, and how far they're travelling. A one-person operation working out of a van in Braunton has different costs to cover than a larger firm with a office and several engineers on the road, and that shows up in the price.
When you call, ask three things: what's included in the price, whether VAT is already in the figure quoted, and whether there's a separate callout charge on top. Getting those answers up front avoids the slightly awkward moment at the end of a job where an extra line item appears that nobody mentioned on the phone.