Viessmann VITODENS 300 Service Instructions Manual page 90

Troubleshooting
Repairs
(cont.)
Extension kit for heating circuit with mixer
Checking the rotational direction of the mixer motor
A Rotational direction switch
B ON/OFF switch "8"
90
1. Switch the ON/OFF switch at the
motor first OFF and then ON again.
The device will carry out the follow-
ing self-test:
Mixer close (150 s)
Pump ON (10 s)
Mixer open (10 s)
Mixer close (10 s)
Then standard control mode
resumes.
2. Note the rotational direction of the
mixer motor during its self-test.
Then set the mixer manually to
"Open" again.
Note
The flow temperature sensor must
now sense a higher temperature. If
the temperature falls, either the
motor is turning in the wrong direc-
tion or the mixer set is incorrectly
fitted.
Mixer installation instruc-
tions
3. Adjust the rotational direction of the
mixer motor (if required).
Switch position I for central heat-
ing return from the left (delivered
condition).
Switch position II for central heat-
ing return from the right.