BoilerFaultCodes AL High
Boiler Fault Code AL
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code AL appears across 1 boiler brand and 1 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 general problem and is waiting for a specific sub-code to appear to tell you exactly what is wrong. (As reported on Sime Mia 30)
Pick your boiler brand for the AL fix
Source
Information for the AL 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