How much does it cost to fix boiler error code 0.5 bar?

Typical repair cost for the boiler 0.5 bar fault is £80-120 including labour.

0.5 bar High

Boiler Fault Code 0.5 bar

Also written as 05BAR — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed 7 July 2026

Fault code 0.5 bar 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 has detected that the water pressure in your heating system has dropped too low to operate safely. (As reported on Keston R-sm 20 FB)

Pick your boiler brand for the 0.5 bar fix

Keston 0.5 bar 1 model

Source

Information for the 0.5 bar 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