BoilerFaultCodes 139 Low
Boiler Fault Code 139
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 139 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 performing a routine self-cleaning cycle to automatically remove trapped air from its internal system. (As reported on Alpha E-Tec Plus NX)
Pick your boiler brand for the 139 fix
Source
Information for the 139 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