BoilerFaultCodes Fault 51 122 Medium
Boiler Fault Code Fault 51 122
Also written as FAULT51122 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code Fault 51 122 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 has detected that the wrong type of temperature sensor has been installed or configured for your hot water cylinder. (As reported on Worcester Bosch Greenstar CDi Compact)
Pick your boiler brand for the Fault 51 122 fix
Source
Information for the Fault 51 122 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