Venting The Boiler; Venting The Heating System - Viessmann VITODENS 222-F Installation And Service Instructions Manual

Commissioning, inspection, maintenance
Further details regarding the individual steps

Venting the boiler

Venting the heating system

1. Close the gas shut-off valve and
switch ON the control unit.
2. Activate venting program (see next
steps).
Note
For function and sequence of the
venting program, see page 121.
3. Check the system pressure.
26
(cont.)
1. Close the shut-off valves on the heat-
ing water side.
2. Remove cover panel A.
3. Connect the drain hose on valve B
with a drain.
4. Open air vent valve B and fill valve
C in the heating return and vent
using mains pressure (flush) until no
more air noise can be heard.
5. Close valve B and fill valve C in the
heating return, and open the shut-off
valves on the heating water side.
Activating venting function with
weather-compensated control unit:
1. Press OK and simultaneously for
approx. 4 s.
2. "Service functions"
3. "Air vent valve"
4. Ending venting function:
Press OK or .