F003 High
Your boiler has shut down because the internal gases leaving the system have become too hot, which is a safety feature to prevent damage to the internal components.
Technical description: Flue gas temperature too high
Typical repair cost: £120-450 (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 F003 — no call-out fees, no surprises.
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Parts commonly replaced
- Heat exchanger
- Flue gas sensor
- Main PCB
- Insulation door
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