BoilerFaultCodes 391 Medium
Boiler Fault Code 391
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 391 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 has lost its connection to the remote thermostat or controller you use to set your heating temperature. (As reported on ECA FELiS FL 50 HM)
Pick your boiler brand for the 391 fix
Source
Information for the 391 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