03 Emergency

Saunier Duval 03 Fault Code

The Saunier Duval 03 fault code means: your boiler is struggling to clear exhaust gases effectively, meaning it has shut down as a safety precaution to prevent dangerous fumes from staying inside.. It appears on 3 Saunier Duval 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: Air fault lock
Typical repair cost £150-350 (including labour)

Engineer required

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

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Saunier Duval models that show the 03 fault code

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

Source

Saunier Duval 03 fault code information on this page is sourced and cross-checked against the official Saunier Duval service / installation manuals for each affected model.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026