BoilerFaultCodes ALL 27 Medium
Boiler Fault Code ALL 27
Also written as ALL27 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code ALL 27 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 electronic control system is incorrectly detecting or misinterpreting the settings for a solar thermal water heating system that may not be present or is not communicating correctly. (As reported on Sime Murelle Elite HE Combi)
Pick your boiler brand for the ALL 27 fix
Source
Information for the ALL 27 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