Draining The Boiler On The Heating Water Side - Viessmann VITODENS 222-F Installation And Service Instructions Manual

Troubleshooting
Repairs
(cont.)

Draining the boiler on the heating water side

Fig. 49
1. Close the shut-off valves on the heating water side.
2. Connect hose to air vent valve
a suitable container or drain outlet.
3. By means of an actuator test, move the 3-way
valve to its centre position.
90
A
4. Open air vent valve
and route it into
A
and drain the boiler as
A
much as required.