Boiler Repair Cost 2026: What You Should Pay
Most boiler repairs cost between £150 and £500 including parts and labour — but the number depends almost entirely on which component failed, and nobody can know that until an engineer has looked. Here are the typical ranges by fault, the repair-versus-replace maths engineers actually use, and what a fair quote should show.
How much does a boiler repair cost?
Most boiler repairs fall between £150 and £500 including parts and labour. That range is wide for a reason: the cost is driven almost entirely by which component failed, and that cannot be known until an engineer has looked at it. The table below shows what typically sits where, so you can sanity-check a quote rather than guess.
| What went wrong | Typical range | Why it varies |
|---|---|---|
| Diagnostic call-out | £60 – £120 | Often deducted from the repair if you go ahead |
| Thermostat or pressure fault | £150 – £250 | Usually parts-light, one visit |
| Pump or diverter valve | £250 – £450 | Part cost varies by make and access |
| Fan or gas valve | £300 – £500 | Manufacturer-specific parts |
| PCB (circuit board) | £400 – £600 | Expensive part; often a replace-vs-repair trigger |
| Heat exchanger | £500 – £800+ | Labour-heavy; frequently uneconomic on an old boiler |
These are ranges, not a quote — the real number depends on the fault, the make and your area. Get my exact price →
Repair or replace? The honest maths
Engineers see the same decision every week, and the arithmetic is usually straightforward once you know three things: the boiler's age, whether parts are still made for it, and what the repair costs relative to a new unit.
- Under 8 years old, part available — repair. The boiler has years of life left and a replacement cannot be justified on efficiency alone.
- 8–12 years old — judgement call. If the repair is under about a third of replacement cost and nothing else is failing, repair. If this is the second fault in a year, start pricing a replacement.
- Over 12 years old, or parts obsolete — usually replace. You are paying to keep an inefficient appliance alive, and the next failure is rarely far away.
If you land on replacement, our boiler replacement cost guide has the current ranges, and the boiler cost calculator will get you closer before you speak to anyone.
What a fair repair quote looks like
- The diagnosis is stated in writing — which part, and why it failed.
- Parts and labour are separated, not merged into one round number.
- The call-out fee is explained, including whether it comes off the repair.
- Any guarantee on the repair is named, with its length.
- The engineer's Gas Safe registration number appears on the paperwork.
- If replacement is recommended, you are given the reason, not just a sales pitch.
⚠ Gas safety: if you smell gas or suspect carbon monoxide, do not wait for a quote. Leave the property, and call the National Gas Emergency Service on 0800 111 999.
How long does a repair take?
Most repairs are a single visit of one to two hours where the engineer already carries the part. Where a component must be ordered, a return visit within a few days is normal. Winter demand lengthens waits — the first cold snap of the year is when every heating engineer's diary fills at once, which is the practical argument for an annual boiler service before the season rather than after a breakdown.
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