Checking The Expansion Vessel And System Pressure; Checking All Connections On The Heating Water And Dhw Sides For Leaks; Releasing The Outdoor Unit Transport Bracket - Viessmann VITOCAL 150-A Installation And Service Instructions Manual

Commissioning, inspection, maintenance

Checking the expansion vessel and system pressure

Use the calculation to DIN 4807-2 to check whether
■
the installed expansion vessel is adequate for the
system water volume.
If the expansion vessel fitted is insufficient, equip the
secondary circuit on site with an additional expan-
sion vessel.
Check the pre-charge pressure of the expansion
■
vessel once a year.
Carry out this test on a cold system.
1. Drain the system until "0" is shown on the pressure
indicator.
Calling up system pressure
Operating instructions.

Checking all connections on the heating water and DHW sides for leaks

Danger
There is a risk of electric shock from escaping
heating water or DHW.
When commissioning and after carrying out
maintenance work, check all water side connec-
tions for leaks.

Releasing the outdoor unit transport bracket

!
Please note
Premature loosening of the transport bracket
may cause damage to the outdoor unit.
Only release the transport lock once the sys-
■
tem has been completely filled and vented.
■ Re-engage the transport lock before topping
up heating water.
86
2. If the pre-charge pressure of the expansion vessel
is lower than the static system pressure: Top up
with nitrogen at the valve of the diaphragm expan-
sion vessel until the pre-charge pressure is 0.1 to
0.2 bar (10 to 20 kPa) higher than the static system
pressure.
Note
■ Do not allow the pre-charge pressure to fall
below 0.7 bar (70 kPa) (boiling noises).
■ Factory-set pre-charge pressure: 0.75 to 0.95 bar
(75 to 95 kPa)
3. Top up with water until the charge pressure of the
cooled system is at least 1.0 bar (0.1 MPa), and is
0.3 to 0.5 bar (30 to 50 kPa) higher than the pre-
charge pressure of the expansion vessel: See
chapter "Filling the system".
Permiss. operating pressure: 3 bar (0.3 MPa)
!
Please note
Leaking hydraulic connections lead to appliance
damage.
■ Check the internal and on-site hydraulic con-
nections for leaks.
In the event of leaks, switch off the appliance
■
immediately. Drain the heating water. Check
the seating of seal rings. Always replace dis-
placed seal rings.