Viessmann D6 Error ((hot)) Jun 2026

On many Viessmann Vitodens models, the D6 code indicates that the burner is blocked because the minimum required flow rate has not been achieved. Essentially, the boiler doesn't "feel" enough water moving through the heat exchanger to safely ignite. Common causes include: in the internal circulation pump. Low system pressure (check if it is below 1.0 bar).

that prevents the "draft" (the flow of air and exhaust) from being established What the Error Means viessmann d6 error

: An internal fault within the main control unit itself that prevents it from processing incoming data. Recommended Troubleshooting On many Viessmann Vitodens models, the D6 code