BoilerFaultCodes RY4 Not Energised High
Boiler Fault Code RY4 Not Energised
Also written as RY4NOTENERGISED — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code RY4 Not Energised appears across 1 boiler brand and 4 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 start because it cannot confirm that the air circulation inside is safe, causing it to lock itself to prevent an unsafe condition. (As reported on Ferroli Arean)
Pick your boiler brand for the RY4 Not Energised fix
Source
Information for the RY4 Not Energised 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