Viessmann B2UA, Installation And Service Instructions Manual

Page: 46 / 200

46
A
B
Shown with connection set for finished walls (accessories)
1. Check the pre-charge pressure of the
diaphragm expansion vessel. See
page 69.
2. Close the gas shut-off valve.
3. Open shut-off valves B on the heat-
ing water side.
4. Fill the heating system via boiler drain
& fill valve
A in the heating return
(depending on the connection set
either on the side or above the boiler).
■ Minimum system pressure
> 1.0 bar (0.1 MPa).
■ Permissible operating pressure
3.0 bar (0.3 MPa).
Note
If the control unit has not been
switched on prior to filling the system,
then the servomotor of the diverter
valve will still be in its central position,
and the system will be completely fil-
led.
5. If the control unit had already been
switched on before filling began:
Switch control unit ON and activate fill
program (see next chapter).
Note
If the control unit has not been
switched on prior to filling the system,
then the servomotor of the diverter
valve will still be in its central position,
and the system will be completely fil-
led.
6.
Close boiler drain & fill valve
A
.
Activating the filling function
Service menu
1. Press
OK and
å
simultaneously for
approx. 4 s.
2. "Service functions"
3. "Filling"
Filling function is enabled.
4. Ending filling function:
Press OK or
ä
.
Commissioning, inspection, maintenance
Further details regarding the individual steps
(cont.)
5773 238 GB