Checking The Diaphragm Expansion Vessel And System Pressure - Viessmann Vitodens 333-F Service Instructions Manual

Further details regarding the individual steps
Checking the diaphragm expansion vessel and system pres-
sure
Note
Carry out this test on a cold system.
1. Drain the system, until the pressure
gauge indicates "0".
2. If the diaphragm expansion vessel
inlet pressure is lower than the sta-
tic system pressure: Top up with
nitrogen via connection A, until
the inlet pressure is 0.1 to 0.2 bar.
Commissioning, inspection, maintenance
(cont.)
3. Top up your heating system with
water and vent until the filling pres-
sure of a cooled system is 0.1 to
0.2 bar higher than the inlet pres-
sure of the diaphragm expansion
vessel.
Permiss. operating pressure: 3 bar
29