BoilerFaultCodes d5 Medium
Boiler Fault Code d5
Also written as D5 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code d5 appears across 1 boiler brand and 6 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is struggling to accurately read the temperature of the water being sent out to your radiators because a sensor responsible for monitoring this flow has developed a fault. (As reported on Worcester Bosch Greenstar 25 HE Combi)
Pick your boiler brand for the d5 fix
Source
Information for the d5 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