BoilerFaultCodes F.671 Low
Boiler Fault Code F.671
Also written as F671 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F.671 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 is having trouble communicating with the solar energy system that helps heat your home, likely due to a faulty electrical connection or sensor. (As reported on Viessmann Vitodens 222-F B2TF)
Pick your boiler brand for the F.671 fix
Source
Information for the F.671 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