Boiler Fault Code Air pressure switch not proved

Also written as AIRPRESSURESWITCHNOTPROVED — same fault.

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

Fault code Air pressure switch not proved appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is failing to detect that the fan is pushing burnt gases safely out of the flue, so it has shut down to prevent unsafe operation. (As reported on Baxi Combi 80e)