BoilerFaultCodes E91 High
Boiler Fault Code E91
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code E91 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 shut down permanently because it tried and failed to restart itself too many times after a recurring technical fault. (As reported on Biasi Rinnova Adaptive Combi)
Pick your boiler brand for the E91 fix
Source
Information for the E91 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