A02 High
Your boiler thinks it sees a flame even though it hasn't started the burner yet, which is a safety conflict that prevents it from running.
Technical description: Flame detected with the burner off – electrode defective main board defective
Typical repair cost: £120-£350 (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 A02 — no call-out fees, no surprises.
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Parts commonly replaced
- Ionisation electrode
- Ignition electrode
- Main PCB
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