23E High
Your boiler has detected a problem with the sensor that monitors exhaust gases, and it has shut down as a safety precaution.
Technical description: Flue sensor damaged
Typical repair cost: £90-180 (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 23E — no call-out fees, no surprises.
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Parts commonly replaced
- Flue Gas NTC Sensor
- Sensor Wiring Harness
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