BoilerFaultCodes 591 High
Boiler Fault Code 591
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 591 appears across 1 boiler brand and 5 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler has detected a communication error with its internal combustion control system, meaning it cannot safely regulate the burner. (As reported on Ariston E-Combi One 30)
Pick your boiler brand for the 591 fix
Source
Information for the 591 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