502 High
Your boiler has detected a flame even though it hasn't signaled for the burner to light, which is a safety conflict that prevents it from running.
Technical description: All Boilers
Typical repair cost: £120-300 (including labour)
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Protect yourself from future repair bills
A boiler cover plan would cover faults like 502 — no call-out fees, no surprises.
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Parts commonly replaced
- Ionisation Probe
- Gas Valve
- Printed Circuit Board (PCB)
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