BoilerFaultCodes F.104 High
Boiler Fault Code F.104
Also written as F104 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F.104 appears across 1 boiler brand and 4 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has received an 'alert' signal from an external part of your heating system, such as a smart thermostat or a safety accessory, which has told the boiler to stop running. (As reported on Viessmann Vitodens 222-F B2TF)
Pick your boiler brand for the F.104 fix
Source
Information for the F.104 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