i23 Low

Boiler Fault Code i23

Also written as I23 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code i23 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 simply displaying its internal software version information rather than reporting a functional problem. (As reported on Worcester Bosch Greenstar Heatslave II)

Pick your boiler brand for the i23 fix

Worcester Bosch i23 1 model

Source

Information for the i23 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