Boiler Fault Code ALL 13

Also written as ALL13 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026

Fault code ALL 13 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 has detected that the gases produced during burning are not escaping properly, so it has safely shut down to prevent the build-up of dangerous fumes. (As reported on Sime Murelle HE System)