Bat Low

Boiler Fault Code Bat

Also written as BAT — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code Bat 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 back-up battery for the safety monitoring system is low or failing and needs replacing. (As reported on Baxi Assure)

Pick your boiler brand for the Bat fix

Baxi Bat 1 model

Source

Information for the Bat 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