F031 High
Your boiler has stopped working because one of its internal heat sensors is reporting a fault, meaning the system can no longer safely monitor the water temperature.
Technical description: Sensor fault S1
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 F031 — no call-out fees, no surprises.
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Parts commonly replaced
- Flow temperature sensor (S1)
- Sensor wiring harness
- Printed Circuit Board (PCB)
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