Viessmann VITOCAL 300-A Installation And Service Instructions Manual page 107

Further details regarding the individual steps
A Quick-acting air vent valve
Type AW-O-M
Manual air vent valve B and fill & drain valve C installed on site inside the
building.
1. Open any on-site non-return
valves installed.
2. Check the pre-charge pressure of
the expansion vessel (see
page 107).
3. Thoroughly flush the on-site pipe-
work.
4. Fill the heating circuit via fill &
drain valve C with water; during
filling, check the system pressure
at the pressure gauge.
Minimum system pressure:
0.8 bar
Permiss. operating pressure:
3 bar
5. Close fill & drain valve C.
6. Slightly open quick-acting air vent
valve A (remains open).
7. Open manual air vent valve B.
Commissioning, inspection, maintenance
(cont.)
B Manual air vent valve
C Fill & drain valve
!
Please note
8.
To prevent equipment
damage, check the flow
and return connections of
the secondary heat pump
circuit for leaks.
In case of leaks, immedi-
ately shut off the equip-
ment, drain the water and
check the seating of the
seal rings. Replace all seal
rings that may have
slipped.
9.
Set the operating mode selector
to "9".
10. Switch ON the power.
11. Close manual air vent valve B
after complete venting.
12. Check the system pressure and
top up with water if required.
107