BoilerFaultCodes ALL 09 High
Boiler Fault Code ALL 09
Also written as ALL09 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code ALL 09 appears across 1 boiler brand and 9 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 water is not moving through your heating system correctly, which is preventing it from heating your home or water. (As reported on Sime Murelle Advanced HE MkII Combi)
Pick your boiler brand for the ALL 09 fix
Source
Information for the ALL 09 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