FH Low

Boiler Fault Code FH

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code FH appears across 1 boiler brand and 8 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler is currently running an automated air purging cycle to remove trapped air bubbles from the system, which is a normal process after installation or maintenance. (As reported on Ferroli Bluehelix Pro RRT)

Pick your boiler brand for the FH fix

Ferroli FH 8 models

Source

Information for the FH 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 7 July 2026