BoilerFaultCodes 0.5 High
Boiler Fault Code 0.5
Also written as 05 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 0.5 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 water pressure is outside the required range, meaning it needs a simple top-up to function correctly. (As reported on Malvern TenTwenty)
Pick your boiler brand for the 0.5 fix
Source
Information for the 0.5 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