Low
C4 273 on Worcester Bosch 30i Junior

Your boiler's fan was spinning when it was supposed to be stopped, often caused by strong winds or a sensing fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

Airflow present during last 24 hour

DIY fix possible

Press and hold the 'Reset' button for five secondsEnsure there are no external obstructions blocking the flue terminal outsideMonitor the boiler for a recurring lockout which may indicate a part failure

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