133 High

Boiler Fault Code 133

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 133 appears across 4 boiler brands and 32 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler has tried to light several times but cannot establish a stable flame, meaning it cannot provide heating or hot water. (As reported on Potterton Promax Combi HE Plus)

Pick your boiler brand for the 133 fix

Atag 133 4 models Baxi 133 26 models Main 133 1 model Potterton 133 1 model

Source

Information for the 133 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