BoilerFaultCodes 213 / D4 High
Boiler Fault Code 213 / D4
Also written as 213D4 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 213 / D4 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 has detected that the water leaving it is much hotter than the water returning, suggesting a blockage or a problem with how water is circulating around your heating system. (As reported on Worcester Bosch Greenstar CDi Compact)
Pick your boiler brand for the 213 / D4 fix
Source
Information for the 213 / D4 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