Viessmann VITOLADENS333-F Service Instructions Manual page 81

Repairs
(cont.)
2. Change over the rotational direc-
tion switch:
Switch position I for central heating
return from the left (delivered con-
dition).
Switch position II for central heat-
ing return from the right.
Checking the Vitotronic 200-H (accessories)
The Vitotronic 200-H is connected to the control unit via the LON system. To
test the connection, carry out a subscriber check at the boiler control unit (see
page 39).
Troubleshooting
81