Boiler Fault Code ALL 96

Also written as ALL96 — same fault.

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

Fault code ALL 96 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 has detected that the exhaust pipe leading outside is blocked or restricted, so it has safely shut itself down to prevent fumes from building up inside your home. (As reported on Sime Murelle Advanced HE Combi)