9.A Low

Boiler Fault Code 9.A

Also written as 9A — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 9.A 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 control panel has been set to stay on permanently, which means it isn't following your usual heating schedule or thermostat settings. (As reported on Worcester Bosch Greenstar CDi Compact)

Pick your boiler brand for the 9.A fix

Worcester Bosch 9.A 1 model

Source

Information for the 9.A 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