612 High
Your boiler's fan is not reaching the required speed, which means the system cannot safely clear exhaust gases and will not fire up.
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Typical repair cost: £180-350 (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 612 — no call-out fees, no surprises.
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Parts commonly replaced
- Fan assembly
- Main PCB
- Venturi tube
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