High
E03 on Saunier Duval Thelia 23E

Your boiler is struggling to clear exhaust fumes safely, so it has purposefully shut down to prevent any risk to your home.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

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

Air pressure switch fault

Engineer required

This is a high 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

E02View →E06View →

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