How much does a boiler repair cost in London?
A typical London boiler repair costs £150–£400 including parts, with most common faults (diverter valves, pumps, PCB sensors) landing around £240. A full PCB replacement can reach £500+.
Low
£150
Typical
£240
per repair
High
£400
Based on London market research, updated July 2026. First-party London Heroes data will replace this as jobs complete.
These are market-research figures, not London Heroes job data. London Heroes publishes what its own completed jobs cost in the London Home Repair Index, job by job, as they complete.
Common faults and typical costs
Diverter valve replacement typically runs £180–£350. Central heating pump replacement £150–£300. Printed circuit board (PCB) faults are the expensive end at £300–£550 — at which point, on an older boiler, engineers will discuss whether repair still makes sense.
Diagnosis usually takes the first 30–60 minutes. A good engineer explains the fault, the part needed, and the total before continuing.
Repair or replace?
The rule of thumb most engineers use: if the boiler is over 10 years old and the repair exceeds a third of replacement cost, get a replacement quote before committing. A modern boiler also cuts gas bills, which changes the maths.
Common questions
Who can legally repair a gas boiler?
Not sure yet what needs doing? Boiler not working: causes and what to do goes through the likely causes and what you can check before you pay for a call-out.
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Reviewed by the London Heroes Operations Team · Last reviewed: . This guide is general information, not a quote or a substitute for advice from a qualified professional.