BoilerFaultCodes C1 29 High
Boiler Fault Code C1 29
Also written as C129 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code C1 29 appears across 1 boiler brand and 4 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler's air circulation system isn't starting, which prevents the unit from firing up safely to provide heat or hot water. (As reported on Atag A200)
Pick your boiler brand for the C1 29 fix
Source
Information for the C1 29 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