BoilerFaultCodes F.517 High
Boiler Fault Code F.517
Also written as F517 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F.517 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 is struggling to communicate with its external control panel or thermostat, which may prevent it from receiving instructions to turn on your heating or hot water. (As reported on Viessmann Vitodens 200-W B2HF System)
Pick your boiler brand for the F.517 fix
Source
Information for the F.517 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