Boiler Fault Code 241 / D1

Also written as 241D1 — same fault.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026

Fault code 241 / D1 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 lost its connection to a temperature sensor and is unable to accurately measure the water returning to it, so it has shut down as a precaution to prevent overheating. (As reported on Worcester Bosch Greenstar CDi Compact)