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.
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?
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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.