Emergency
E03 on Halstead Eden CBX/SBX

Your boiler has detected an issue with the ventilation system or internal fan, which prevents it from safely getting rid of waste gases.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

Technical description

Flue thermostat operation (applicable to certain models) / Fan failure

Engineer required

This is a emergency severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

E01View →E02View →

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