Boiler Fault Code No Fan Run

Also written as NOFANRUN — same fault.

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

Fault code No Fan Run appears across 1 boiler brand and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has stopped working because it cannot detect that water is flowing through it properly, so it has shut down to prevent internal damage. (As reported on Potterton Promax 15 & 24)