31 High
Your boiler has detected that the exhaust gases are not being monitored correctly and has shut down for safety.
Technical description: Failed flue temperature – the flue sensor needs checking or replacing
Typical repair cost: £120-220 (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 31 — no call-out fees, no surprises.
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Parts commonly replaced
- Flue Gas Sensor
- Wiring Harness
- Main PCB
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