Viessmann D6 Error Review

However, if your boiler is more than 12 years old and the D6 error recurs weekly despite new wiring, the Vitotronic main board may be reaching end-of-life. At that point, compare the cost of a new board versus a partial boiler replacement—especially if other components like the fan or heat exchanger are also aging.

Any work involving the gas supply or internal electrical wiring must be carried out by a Gas Safe registered engineer . Viessmann Fault Code Checker viessmann d6 error