Changeover Unit Of The Automatic Charging System; Checking The Diaphragm Expansion Vessel And System Pressure - Viessmann VITOLIG 300 Service Instructions Manual

10. Changeover unit of the automatic charging system

1. Check changeover unit A for
leaks and ease of operation.
11. Checking the diaphragm expansion vessel and system pres-
sure
Observe the diaphragm expansion vessel manufacturer s instructions.
Carry out this test on a cold system.
1. Drain the system or close the cap
valve on the diaphragm expansion
vessel and reduce the pressure,
until the pressure gauge indi-
cates "0".
Inspection and maintenance
2. With the wand changeover, control
all wands and supply pellets by
way of testing.
Operating instructions
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 above (0.1
to 0.2 bar) the static system pres-
sure.
The static pressure corresponds to
the static head.
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