C High

Baxi C Fault Code

The Baxi C fault code means: your boiler has stopped working because it cannot communicate properly with its internal exhaust fan, which is crucial for safety and operation.. It appears on 5 Baxi models in our database.

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

Technical description: Fan connections check / Fan jammed or faulty wiring
Typical repair cost £150-300 (including labour)

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Baxi models that show the C fault code

Click a model for the full fault code list and model-specific repair notes.

Source

Baxi C fault code information on this page is sourced and cross-checked against the official Baxi service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026