High
Air Proving LOCKOUT on Potterton Suprima HE

Your boiler has stopped working because it cannot confirm that air is moving through the system correctly, which is a safety mechanism to prevent the burner from starting improperly.

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

Manual reset. Air Proving Switch (APS) fails to operate correctly or remains 'On' when it should be 'Off'.

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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