Viessmann Vitodens 222-F B2TA Installation And Service Instructions Manual page 36

Commissioning, inspection, maintenance
Further details regarding the individual steps
Shown with connection set for finished walls (accessories)
1. Check the pre-charge pressure of the
diaphragm expansion vessel (see
page 61).
2. Close the gas shut-off valve.
3. Open shut-off valves B on the heat-
ing water side.
4. Fill the heating system via boiler drain
& fill valve A in the heating return (at
the connection set on the side or
above the boiler). Minimum system
pressure > 1.0 bar (0.1 MPa).
Note
If the control unit has not been
switched on prior to filling the system,
then the servomotor of the diverter
valve will still be in its central position,
and the system will be completely fil-
led.
36
(cont.)
A
5. If the control unit had already been
switched on before filling began:
Switch control unit ON and activate fill
program (see next chapter).
Note
For function and details of the fill pro-
gram, see page 161.
6. Close boiler drain & fill valve A.
B