Checking The Diaphragm Expansion Vessel And System Pressure - Viessmann Vitodens 100 Series Installation And Service Instructions Manual

Commissioning, inspection, maintenance
Further details regarding the individual steps
5. Re-establish gas supply. Switch ON
the power supply.
Checking the diaphragm expansion vessel and system pres-
sure
Carry out this test on a cold system.
1. Switch ON the control unit. Close
the gas shut-off valve.
2. Use / to select "IF00"
The main display shows the current
pressure in MPa.
3. Drain the system or close the cap
valve on the expansion vessel and
reduce the pressure until 0 MPa is
shown.
4. If the pre-charge pressure of the
expansion vessel is lower than the
static system pressure, top up with
nitrogen until the pre-charge pres-
sure is 0.01 to 0.02 MPa higher
than the static system pressure.
52
(cont.)
6. Check the gas connections for
leaks.
Danger
Escaping gas leads to a risk
of explosion.
Check the fitting for gas
tightness.
!
Please note
The use of leak detection
spray can result in faulty
operation.
Leak detection spray must
not come into contact with
electrical contacts or block
the diaphragm opening on
the gas valve.
5. Top up with water (see page 35)
until the charge pressure of the
cooled system is at least 0.08 MPa,
and is 0.01 to 0.02 MPa higher than
the pre-charge pressure of the
expansion vessel.
Permiss. operating pressure:
(0.3 MPa)