Returning The Dhw Cylinder Into Use; Checking The Diaphragm Expansion Vessel And System Pressure - Viessmann VITODENS 333-F WS3A Service Instructions Manual

Commissioning, inspection, maintenance
Further details regarding the individual steps

Returning the DHW cylinder into use

1. Reconnect the DHW cylinder to the
pipework.
2. Insert new gasket B underneath
flange lid A.
3. Fit the flange lid and tighten the
screws with a maximum torque of
25 Nm.
Checking the diaphragm expansion vessel and system pres-
sure
Note
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 indicates
"0".
24
(cont.)
4. Push earth lead C onto tab D.
5. Fit cover E.
6. Fill the DHW cylinder with potable
water.
2. If the inlet pressure of the dia-
phragm expansion vessel is lower
than the static system pressure,
top up with nitrogen until the inlet
pressure is raised by 0.1 to 0.2 bar.