660 High

Boiler Fault Code 660

Reviewed by the BoilerFaultCodes Editorial Team Last reviewed

Fault code 660 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 an electrical fault within its internal wiring or a control component, causing it to shut down for safety. (As reported on Worcester Bosch WR325 RSF)

Pick your boiler brand for the 660 fix

Worcester Bosch 660 1 model

Source

Information for the 660 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