Checking The Mixer For Obstructions And Leaks - Viessmann VITOROND 100 Service Instructions Manual

Further details regarding the individual steps
Checking the diaphragm expansion vessel and system pressure
Observe the diaphragm expansion vessel manufacturer's instructions.
Carry out this test on a cold system.
1. Drain the system until the
pressure gauge indicates "0" or
close the cap valve on the
diaphragm expansion vessel, and
reduce the pressure on the
primary side of the diaphragm
expansion vessel.
2. If the inlet pressure of the
diaphragm expansion vessel is
lower than the static system
pressure, top up with enough
nitrogen to raise the inlet pressure
higher than the static system
pressure (0.1 to 0.2 bar).
The static pressure corresponds to
the static head.

Checking the mixer for obstructions and leaks

1. Remove the motorised lever from
the mixer handle and check the
mixer for ease of movement.
2. Check the mixer for leaks.
Replace the O rings if the mixer
leaks.
Checking the Vitoair draught stabiliser
Release the latch on the control disc.
The control disc must swing freely
during burner operation.
Initial start−up, inspection and maintenance
3. Top up with water, until the
pressure of a cold system is
higher (0.1 to 0.2 bar) than the
inlet pressure of the diaphragm
expansion vessel.
Permiss. operating pressure: 3 bar
3. Snap the frame into place.
(if installed)
(cont.)
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