BoilerFaultCodes F9 to F0 Low
Boiler Fault Code F9 to F0
Also written as F9TOF0 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F9 to F0 appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is displaying its recent history of errors to help a technician understand what has gone wrong in the past. (As reported on Glow-worm Xtramax HE)
Pick your boiler brand for the F9 to F0 fix
Source
Information for the F9 to F0 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