What boiler repairs typically cost in 2026 — from the call-out fee to a new PCB or fan — plus how to judge repair versus replacement, and how cover can cap the bill.
There's no single number. What you pay depends on the part that's failed, your boiler's age and brand, where you live (London and the South East run noticeably higher than much of the North and Wales), and whether the engineer can fix it in one visit or has to order a part and come back. As a rough guide, a straightforward repair on a modern combi often lands somewhere between £150 and £350 all in, while a major component on an older boiler can climb past £500 — at which point replacement starts to look sensible.
Most independent engineers charge a call-out or diagnostic fee just to attend and find the fault — often £60 to £120, and sometimes more for an emergency or out-of-hours visit. Many will roll that fee into the repair cost if you go ahead with the work, but not all do, so ask. A national repair-and-care provider may quote a fixed price per repair instead, which can be simpler but isn't always cheaper.
The table below covers the parts that fail most often. Each figure is parts and labour together, for a typical domestic combi or system boiler. Heat-only boilers and high-end German brands can sit at the top of these ranges or above.
| Repair | What it does / why it fails | Indicative cost |
|---|---|---|
| PCB (printed circuit board) | The boiler's "brain". Expensive to replace and often a tipping point towards a new boiler on older units. | £300–£600 |
| Pump | Circulates water round the system; a worn pump causes no heat or noisy running. | £200–£400 |
| Fan | Drives the flue gases out. A failed fan usually locks the boiler out on safety. | £200–£450 |
| Gas valve | Controls gas to the burner. A skilled, Gas Safe-only job — never DIY. | £250–£500 |
| Diverter valve | Switches flow between heating and hot water; a common cause of "hot taps but cold radiators" (or vice versa). | £200–£400 |
| Expansion vessel | Absorbs pressure changes; a failed vessel causes pressure that keeps creeping up or dropping. | £150–£350 |
| Thermostat / programmer | Room or boiler thermostat fault — sometimes a cheap fix, sometimes a controls swap. | £80–£250 |
| Flow / pressure sensor | Tells the boiler what's happening with water flow; common cause of intermittent lockouts. | £120–£300 |
Smaller jobs — replacing a faulty thermocouple, clearing an airlock, fitting a new auto air vent — can come in under £150. At the other end, if more than one major part has gone, or the same part keeps failing, the cumulative cost is what tips many people towards a replacement.
Not every "fault" needs an engineer. Before you book a repair, it's worth ruling out the simple stuff. These are all homeowner-safe — none involve removing the boiler casing or touching anything inside it:
There's no hard rule, but a few honest signals point towards replacing rather than repairing:
If your boiler is newer and the fault is a one-off, repair is almost always the right call. Get a Gas Safe engineer to confirm the diagnosis and quote both options before you decide.
The reason repair costs hurt is that they're unpredictable — a fan one winter, a PCB the next. A boiler cover plan swaps that lumpy risk for a fixed monthly cost: you pay a set amount, and the plan picks up the call-out, labour and covered parts when something breaks (subject to your excess, claim limits and exclusions). For an older boiler that's still economical to keep, that can be reassuring — though check the small print, because most plans won't cover a boiler that's "beyond economic repair", and there's usually an initial exclusion period before you can claim.
Whether cover is worth it comes down to your boiler's age, your appetite for surprise bills, and the plan's price against its excess and exclusions. If you want to weigh it up, our cheaper-plan guide and the comparison tool show indicative prices and cover levels side by side. This is information to help you decide, not personal advice.
It depends entirely on the cause. A tripped fuse, low pressure or a frozen condensate pipe can cost nothing to fix yourself. If it's an electrical or gas component — a PCB, fan or gas valve — you're typically looking at £200–£600 once a Gas Safe engineer has diagnosed it.
Repair is usually cheaper in the short term, but on a boiler over about 10–12 years old, a major repair near half the price of a new boiler often isn't worth it — spares are harder to find and another fault may follow. Ask a Gas Safe engineer to quote both.
No. By law, gas boiler repairs must be carried out by a Gas Safe registered engineer. You can safely check the pressure, reset the boiler, check the thermostat and fuse, and thaw a frozen condensate pipe — but anything behind the casing must be left to a professional.
Usually it covers the call-out, labour and covered parts, but most plans have an excess per claim and exclusions — for example pre-existing faults, very old boilers and "beyond economic repair" replacements. Read what's included before you rely on it.
Compare indicative prices and cover levels from our selected panel of providers, then buy direct on their site.
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