BoilerFaultCodesYour boiler has managed to light the small pilot flame, but the main gas burners are failing to ignite to heat your home.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: PILOT LIT BUT NO MAINS GAS
What causes this fault?
This fault occurs when the boiler successfully lights the small starter flame but cannot open the main gas valve to fire up the large burners. The most common reason is a mechanical failure within the internal gas control valve or an electrical fault in the circuit board that prevents it from sending the signal to release the main flow of gas.
This issue is more frequent in winter when the boiler is under high demand, as internal mechanical parts are more likely to seize after being inactive during the summer.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
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A boiler cover plan would cover faults like 52 — no call-out fees, no surprises.
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