F7 High
Your boiler thinks it sees a flame even though it should be turned off, which prevents it from starting up safely.
Technical description: Flame detected even though the appliance is switched off – check the electrode assembly is dry and the pcb and flue are clear.
Typical repair cost: £120-450 (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 F7 — no call-out fees, no surprises.
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Parts commonly replaced
- Ionisation electrode
- Control box (PCB)
- Wiring harness
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