BoilerFaultCodes AL 05 High
Boiler Fault Code AL 05
Also written as AL05 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code AL 05 appears across 1 boiler brand and 22 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 problem with the temperature sensor that monitors the water being sent to your taps and radiators, causing it to stop working as a safety precaution. (As reported on Sime Format DGT HE Combi)
Pick your boiler brand for the AL 05 fix
Source
Information for the AL 05 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