BoilerFaultCodes NO DHW BUT CH ON Medium
Boiler Fault Code NO DHW BUT CH ON
Also written as NODHWBUTCHON — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code NO DHW BUT CH ON 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 successfully heating your radiators, but it is failing to send heat to your hot water tank. (As reported on Johnson Starley J32 System ET)
Pick your boiler brand for the NO DHW BUT CH ON fix
Source
Information for the NO DHW BUT CH ON 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