BoilerFaultCodes 0.45 High
Boiler Fault Code 0.45
Also written as 045 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 0.45 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 not operating correctly because it has detected an internal communication failure between its electronic control boards. (As reported on Johnson Starley Aquair S 10)
Pick your boiler brand for the 0.45 fix
Source
Information for the 0.45 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 7 July 2026