BoilerFaultCodes ALL 28 High
Boiler Fault Code ALL 28
Also written as ALL28 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code ALL 28 appears across 1 boiler brand and 6 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 an issue with how its internal settings are communicating, likely due to a configuration error or a faulty circuit board connection. (As reported on Sime Murelle Elite HE 35T System)
Pick your boiler brand for the ALL 28 fix
Source
Information for the ALL 28 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