BoilerFaultCodes F70 High
Boiler Fault Code F70
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F70 appears across 3 boiler brands and 30 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler's main control board has lost communication with its internal identity chip, effectively meaning the boiler has forgotten which model it is and cannot operate. (As reported on Glow-worm Ultracom 24cx 30cx)
Pick your boiler brand for the F70 fix
Source
Information for the F70 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