C4 273 High
Your boiler has detected that the fan was running or air was moving when it shouldn't have been, causing the system to lock out for safety.
Technical description: Airflow present during last 24 hour
Typical repair cost: £150-£350 (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 C4 273 — no call-out fees, no surprises.
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Parts commonly replaced
- Fan assembly
- Printed Circuit Board (PCB)
- Air Pressure Switch
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