BoilerFaultCodes 253 Medium
Boiler Fault Code 253
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 253 appears across 2 boiler brands and 6 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 a confusing startup signal due to a brief electrical glitch or an internal communication error between its main control boards. (As reported on Navien NCM 1130HH)
Pick your boiler brand for the 253 fix
Source
Information for the 253 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