Boiler Fault Code 341 D4

Also written as 341D4 — same fault.

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

Fault code 341 D4 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 is overheating because the water inside cannot circulate fast enough to move the heat away, so the system has safely shut itself down to prevent damage. (As reported on Worcester Bosch Greenstar CDi Compact)