BoilerFaultCodes 6-tb Low
Boiler Fault Code 6-tb
Also written as 6TB — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 6-tb 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 is currently running a self-diagnostic test to check the burner's performance across its full power range. (As reported on Worcester Bosch Greenstar 2000)
Pick your boiler brand for the 6-tb fix
Source
Information for the 6-tb 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