Fan does not run High

Boiler Fault Code Fan does not run

Also written as FANDOESNOTRUN — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code Fan does not run appears across 4 boiler brands and 5 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 the internal fan, which safely exhausts fumes, isn't starting up. (As reported on Glow-worm Ultimate3)

Pick your boiler brand for the Fan does not run fix

Glow-worm Fan does not run 2 models Potterton Fan does not run 1 model Saunier Duval Fan does not run 1 model Worcester Bosch Fan does not run 1 model

Source

Information for the Fan does not run fault code is sourced from the official service / installation manual for each model that displays it. Read more about how we source fault codes →

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