BoilerFaultCodes No functions High
Boiler Fault Code No functions
Also written as NOFUNCTIONS — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code No functions 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 has lost all power and the display is completely blank because of an internal electrical failure. (As reported on Worcester Bosch Greenstar i)
Pick your boiler brand for the No functions fix
Source
Information for the No functions 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