Boiler Fault Code No light (DHW cold)

Also written as NOLIGHTDHWCOLD — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026

Fault code No light (DHW cold) 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 failing to detect when you turn on the hot tap, meaning it isn't heating the water for your shower or taps. (As reported on Halstead Dimplex Combi)