151 High
Your boiler has detected a problem with the fan or its internal control chip, meaning it cannot safely clear waste gases and will not start.
Technical description: Fan error or control unit defective (speed control is not achieved)
Typical repair cost: £250-£550 (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 151 — no call-out fees, no surprises.
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Parts commonly replaced
- Fan assembly
- Printed Circuit Board (PCB)
- Wiring harness
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