BoilerFaultCodes CA Medium
Boiler Fault Code CA
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code CA appears across 1 boiler brand and 5 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 water is flowing through your hot water system faster than it can heat up, which often points to an issue with how much water is being drawn from your taps. (As reported on Worcester Bosch Greenstar 30si)
Pick your boiler brand for the CA fix
Source
Information for the CA 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