BoilerFaultCodes Case sensor High
Boiler Fault Code Case sensor
Also written as CASESENSOR — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code Case sensor 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 a faulty connection to a safety sensor responsible for monitoring the outer casing, which will prevent the heating and hot water from turning on. (As reported on Potterton Envoy Plus)
Pick your boiler brand for the Case sensor fix
Source
Information for the Case sensor 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 7 July 2026