Viessmann VITODENS 100 Installation And Service Instructions Manual page 49

Commissioning and testing
Venting the boiler by flushing out (after venting system)
(cont.)
1. Leaving the hose connections from
filling the system continue to fill the
boiler from the external filling loop
and draining the water to a drain
from connection D.
2. Continue flushing the water through
the boiler until no air pockets are
discharged out of the drain hose.
3. Slowly turn off the valve D and
turn off the temporary filling loop to
regulate the pressure in the boiler
and system to approx 1.2 bar.
4. Turn valve A to open position
(toggle to rear).
5. Turn on the appliance to circulate
the pump in both DHW and CH
positions in order to continue vent-
ing.
Note
It is essential that there is no air in
the heat exchanger and the system
prior to firing the appliance. This
will cause an F7 fault and prevent
you finishing the installation without
hinderance.
After 12 minutes the electronic
board switches into the DHW
modus. Turn rotary selector "tr"
clockwise for two seconds into the
middle position, then turn rotary
selector "tr" counterclockwise
back to the end stop.
Installation sequence
49