Viessmann Vitoligno 250-S Installation And Service Instructions For Contractors page 60

Extension kit for heating circuit with mixer
Mixer motor
Changing the rotational direction (if required)
1. Danger
An electric shock can be life threatening.
Before opening the boiler, disconnect it from
the mains voltage, e.g. at the fuse or mains
isolator.
Remove the casing cover (see chapter "Overview
of electrical connections").
2.
gS
|
BU
~
Fig. 37
Switch cores BK and BK
60
on plug .
gS
3. Refit the casing cover.
4. Check the rotational direction.