BoilerFaultCodes 53:3 Medium
Boiler Fault Code 53:3
Also written as 533 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code 53:3 appears across 1 boiler brand and 5 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.
Most common meaning Your boiler is having trouble communicating with the pump that fills your separate hot water tank, meaning your home's hot water supply may be affected. (As reported on Viessmann Vitodens 300-W)
Pick your boiler brand for the 53:3 fix
Source
Information for the 53:3 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