Checking The Diaphragm Expansion Vessel Of The Heating Circuit And Its Pressure; Checking The Diaphragm Expansion Vessel Of The Solar Circuit And Its Pressure (Only For The Vitocal 242, If Required) - Viessmann VITOCAL 242-G Installation And Service Instructions Manual

Commissioning, inspection, maintenance
Further details regarding the individual steps
Checking the diaphragm expansion vessel of the heating cir-
cuit and its pressure
Carry out this test on a cold system.
Note
Only use anti-corrosion agents offered by the heating trade that have been
approved for heat pumps with DHW heating via single-walled heat exchangers
(DHW cylinders).
1. Drain the primary side of the boiler
system and reduce the pressure
until pressure gauge D (see
page 108) indicates "0".
2. If the pre-charge pressure of the
diaphragm expansion vessel is
lower than the static system pres-
sure, top up with sufficient nitrogen
to raise the pre-charge pressure
higher than the static system pres-
sure.
Example:
Static head
(distance between the heat
source and the highest
heating surface)
= static pressure
Checking the diaphragm expansion vessel of the solar cir-
cuit and its pressure (only for the Vitocal 242, if required)
Carry out this test on a cold system.
!
Please note
Risk of equipment damage
from incorrect heat transfer
medium concentration.
Only top up with "Tyfocor G-
LS".
106
3. Top up with water, until the filling
pressure exceeds the pre-charge
pressure of the diaphragm expan-
sion vessel.
On a cold system, the fill pressure
must be approx. 0.2 bar higher
than the static pressure.
Max. operating pressure: 3.5 bar.
4. During commissioning, mark this
value on pressure gauge D (see
page 108) as minimum filling value.
10 m
1 bar
(cont.)