BoilerFaultCodes F1263 High
Boiler Fault Code F1263
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code F1263 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's internal computer has developed a fault and can no longer communicate with the main control system, meaning it cannot operate safely. (As reported on Worcester Bosch CDi Classic)
Pick your boiler brand for the F1263 fix
Source
Information for the F1263 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