Boiler Fault Code 299

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 31 August 2026

Fault code 299 appears across 2 boiler brands and 14 models. The exact meaning varies by manufacturer — pick your boiler brand below to see the model-specific fix.

Most common meaning Your boiler's internal clock has lost track of the time or date, so timed heating and hot water schedules may not run correctly, but the boiler itself is usually still safe to use. (As reported on Viessmann Vitodens 050-W B0HA-19)