BoilerFaultCodes 5 flashes green High
Boiler Fault Code 5 flashes green
Also written as 5FLASHESGREEN — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 5 flashes green 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's internal computer is experiencing a configuration error, which prevents it from knowing how to safely operate your heating and hot water. (As reported on Main Insul 7)
Pick your boiler brand for the 5 flashes green fix
Source
Information for the 5 flashes green 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