BoilerFaultCodes Fault 55 / 146 Low
Boiler Fault Code Fault 55 / 146
Also written as FAULT55146 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code Fault 55 / 146 appears across 1 boiler brand and 2 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is displaying an advisory message stating that its built-in solar heating controls have not been set up or activated. (As reported on Worcester Bosch Greenstar CDi Compact)
Pick your boiler brand for the Fault 55 / 146 fix
Source
Information for the Fault 55 / 146 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