Viessmann VITOCAL 300, Installation And Service Instructions Manual

Page: 44 / 160

Note
Only use anti-corrosion agents that
have been approved for heat pumps
with DHW heating via single-walled
heat exchangers (DHW cylinders).
1. Drain the heating water side of the
boiler system and reduce the pres-
sure until the pressure gauge indi-
cates "0".
2. If the inlet pressure of the dia-
phragm expansion vessel is lower
than the static system pressure,
top up with sufficient nitrogen to
raise the inlet pressure higher than
the static system pressure.
Example:
Static head
(distance between the
heat source and the
highest heating surface) 10 m
= static pressure 1 bar
3. Top up with water, until the filling
pressure exceeds the inlet pres-
sure of the diaphragm expansion
vessel.
On a cold system, the filling pres-
sure must be approx. 0.2 bar higher
than the static pressure.
Max. operating pressure: 4 bar.
4. During commissioning, mark this
value on the pressure gauge as
minimum filling pressure.
Only for type BWC: Filling the primary circuit and checking
the pressure
1. Only for commissioning:
Flush the primary circuit.
2. Only for commissioning:
Fill the primary circuit with heat
transfer medium "Tyfocor -15 ° C"
and vent the circuit.
3. Check the primary circuit pressure.
The pressure should be approx.
2 bar.
4. Check the inlet pressure of the dia-
phragm expansion vessel and
adjust, if required (see page 43).
Further details regarding the individual steps
(cont.)
44
Commissioning, inspection, maintenance
55
92
901
GB