BoilerFaultCodes 9-11 High
Boiler Fault Code 9-11
Also written as 911 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 9-11 appears across 1 boiler brand and 1 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your heat pump is unable to move water around the system correctly, which means your heating and hot water will stop working until the connection or pump is repaired. (As reported on Ideal Logic Air)
Pick your boiler brand for the 9-11 fix
Source
Information for the 9-11 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