Boiler Fault Code Fan operation indicator

Also written as FANOPERATIONINDICATOR — same fault.

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

Fault code Fan operation indicator 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's fan system is running correctly to safely remove exhaust gases, and the indicator light is simply confirming that this part of the startup process is working as intended. (As reported on Vaillant Turbomax VU 182)