BoilerFaultCodes AL 93 High
Boiler Fault Code AL 93
Also written as AL93 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code AL 93 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 is struggling to burn gas correctly and is failing to reach its required performance levels, causing the system to shut down for safety. (As reported on Sime Brava One HE)
Pick your boiler brand for the AL 93 fix
Source
Information for the AL 93 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