Boiler Service Cost Guide (2026)

What a gas boiler service costs in 2026

These are the going rates among firms local to Maidstone and mid-Kent that publish prices. To be clear, it’s a survey of the market, not our price list — how we price is covered further down. Some of the numbers are cheap, and we’ve included them because you’ll come across them anyway. Just ask what you’re actually getting before you book one.

• Around Maidstone and mid-Kent, published prices run from about £75 at the budget end up to £120 at the top.
• Nationally, £100 or so is the figure most often quoted for a proper annual service.
• The difference is mostly what gets done in the visit. A proper service takes about an hour with the casing off and includes a flue gas analysis — that can’t be done at the price of a quick once-over. The full checklist is below, and it’s the job we do on every service.
• Older or awkward boilers can add a bit to any firm’s price, and so can a first visit to a boiler nobody holds records for — it just takes longer.

Landlord certificates (CP12) and service bundles

If you let out a property, an annual gas safety check is a legal requirement, and the record — the CP12 — is a separate job from a service, though the two are best done in one visit.

• A CP12 on its own: typically £60–£90 across Kent, with firms nearer London at the top of the range and beyond it.
• Service and CP12 together: local and South East firms publish bundle prices in the £96–£109 range — noticeably cheaper than booking the two separately, because the engineer is only travelling once.
• One visit also means one appointment for your tenant to be in for — if you’ve ever tried to arrange access twice in a month, that’s worth as much as the saving.
• This is how we do it ourselves: the CP12 alongside the service in one visit, a copy emailed over for your records, and discounts if you’ve got more than one property with us.

What should be included for the money

A proper annual service means the casing off and the engineer inside the boiler. If yours was done in fifteen minutes, it was a look-over, not a service. Before you compare prices, check what’s included — everything on this list is included in a standard Plumbusters service:

• A flue gas analysis — the instrument test that shows the boiler is burning cleanly and efficiently. If a cheap service skips anything, it’s usually this.
• The working parts inspected — burner, heat exchanger, ignition and fan, seals, condensate trap
• Gas pressure and gas tightness checks, plus the flue itself
• System pressure and the expansion vessel checked, and the magnetic filter given a clean if you have one
• Safety devices and controls tested, and a written record left with you afterwards

And if the service turns something up — what repairs cost

Repair pricing is done two ways, and it’s worth knowing both before you need one. The nationals sell fixed-price repairs: British Gas advertises a one-off repair at around £295 and 24|7 Home Rescue around £349, while BOXT charges £89 to diagnose with parts on top. Local firms — us included — mostly charge for the call-out or first hour (published Kent figures run £84–£99) and then quote for the fix once the fault is known.

A fixed price sounds reassuring, but you pay the same £295 whether the fault turns out to be a £6 sensor or a £200 valve. Paying for a diagnosis and then a quoted repair usually works out cheaper, and you actually get told what was wrong. That’s how we do it: find the fault, quote it in writing, and nothing gets replaced until you’ve said yes.

Getting a price from Plumbusters

No two jobs price quite the same. A newish combi is a different visit from a twenty-year-old back boiler, and where you are makes a difference too — so we price each job on what it actually is rather than working off a set menu. Tell us your postcode and what you’ve got, and you’ll have a firm figure on the phone with nothing added on the day. We’re a family firm and that’s how we’ve worked for over 30 years: the price we agree is the price you pay.

It’s the same Gas Safe team whichever way you want to do it: a one-off annual service, a landlord’s service with the CP12 done in the same visit (and discounts if you’ve more than one property with us), or a service contract where the booking becomes our job — a full service every year, with a reminder when it’s due. That last one is a service contract, not insurance: no excess, no claims process, and if the service turns anything up we quote the repair separately before touching it. Ring 01622 474008 or request a call back and we’ll sort whichever suits.