High
40-60-80 (ll-ll-ll) on Ariston Clas HE 35

Your boiler is struggling because it cannot detect that it is successfully pulling fresh air in and pushing exhaust fumes out, so it has stopped running to keep you safe.

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

Fan on but does not activate air pressure switch

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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