BoilerFaultCodes Fault 53 / 125 High
Boiler Fault Code Fault 53 / 125
Also written as FAULT53125 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code Fault 53 / 125 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 a temperature sensor is installed in the wrong place, meaning the system cannot accurately monitor the heat coming from your solar panels or heating circuit. (As reported on Worcester Bosch Greenstar CDi Compact)
Pick your boiler brand for the Fault 53 / 125 fix
Source
Information for the Fault 53 / 125 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