BoilerFaultCodes A0:2 Medium
Boiler Fault Code A0:2
Also written as A02 — same fault.
Reviewed by the BoilerFaultCodes Editorial Team Last reviewed
Fault code A0:2 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 has lost communication with your wall-mounted remote control unit, meaning the thermostat cannot talk to the boiler to manage your heating. (As reported on Viessmann Vitodens 300-W)
Pick your boiler brand for the A0:2 fix
Source
Information for the A0:2 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