E03 Emergency

Halstead E03 Fault Code

The Halstead E03 fault code means: your boiler has detected an issue with the ventilation system or internal fan, which prevents it from safely getting rid of waste gases.. It appears on 6 Halstead models in our database.

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
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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Halstead models that show the E03 fault code

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

Source

Halstead E03 fault code information on this page is sourced and cross-checked against the official Halstead service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026