Viessmann VITODENS 111-W Installation And Service Instructions Manual page 52

Commissioning, inspection, maintenance
Further details regarding the individual steps
B
A
A Test connector, heating water
expansion vessel
B Test connector, DHW expansion
vessel
Checking the connections on the heating water and the DHW
side
Check all connections and lines on the
heating water and DHW side (including
inside the appliance) for tightness and
possible damage.
Checking all gas equipment for tightness at operating pressure
Danger
Escaping gas leads to a risk of
explosion.
Check all gas equipment for tight-
ness.
52
(cont.)
1. Drain the system until the pressure
gauge shows "0".
2. If the diaphragm expansion vessel
pre-charge pressure is lower than the
static system pressure: Top up with
nitrogen until the pre-charge pres-
sure is 0.1 to 0.2 bar (10 to 20 kPa)
higher.
3. Top up with water until the charge
pressure of the cooled system is at
least 1.0 bar (0.1 MPa), and is 0.1 to
0.2 bar (10 to 20 kPa) higher than the
pre-charge pressure of the expan-
sion vessel.
Permiss. operating pressure: 3 bar
(0.3 MPa)
!
Please note
The use of leak detection spray
can result in faulty operation.