BoilerFaultCodes 1009 B High
Boiler Fault Code 1009 B
Also written as 1009B — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 1009 B 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 boiler's internal pump is not communicating correctly with the main control board, meaning the system cannot circulate hot water around your home. (As reported on Worcester Bosch Greenstar 2000)
Pick your boiler brand for the 1009 B fix
Source
Information for the 1009 B 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 27 April 2026