109 Low

Boiler Fault Code 109

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 109 appears across 8 boiler brands and 54 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has detected that the burner has successfully lit, but this informational status code may indicate a temporary cycle monitoring check or require professional attention if it persists and locks out the system. (As reported on Baxi PLATINUM COMPACT 25 COMBI)

Pick your boiler brand for the 109 fix

Ariston 109 3 models Atag 109 18 models Baxi 109 17 models ECA 109 1 model Main 109 2 models Navien 109 4 models Potterton 109 8 models Worcester Bosch 109 1 model

Source

Information for the 109 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 31 August 2026