BoilerFaultCodes ALL 88 High
Boiler Fault Code ALL 88
Also written as ALL88 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code ALL 88 appears across 1 boiler brand and 3 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler's main control computer is experiencing an internal electronic fault, which has triggered a safety shutdown to prevent further damage. (As reported on Sime Murelle Revolution 30)
Pick your boiler brand for the ALL 88 fix
Source
Information for the ALL 88 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