Venting The Boiler; Venting The Heating System - Viessmann VITODENS 343-F WS4A Installation And Service Instructions Manual

Further details regarding the individual steps

Venting the boiler

1. Close the shut-off valves on the
heating water side.
2. Connect the drain hose to valve B
and connect it to a drain outlet.

Venting the heating system

1. Close the gas shut-off valve and
switch ON the control unit.
Commissioning, inspection, maintenance
(cont.)
3. Open valves A and B, and vent
at mains pressure until no sound of
escaping air can be heard.
4. Close valves A and B and open
the heating water shut-off valves.
2. Activate the venting program via
coding "2F:1".
Note
To call up code 1 and for setting the
coding address, see page 66.
For function and sequence of the
venting program, see page 121.
Whilst the venting program runs,
the display shows "EL" (constant
temperature control unit) or
"Venting" (weather-compensated
control unit).
25