Viessmann Vitocrossal 300 Service Instructions For Contractors page 111

Repairs
(cont.)
Extension kit for heating circuit with mixer
Checking the setting of rotary selec-
tor S1
The rotary selector on the PCB of the
extension kit defines the assignment to
the relevant heating circuit.
Heating circuit
Heating circuit with
mixer M2 (heating cir-
cuit 2)
Heating circuit with
mixer M3 (heating cir-
cuit 3)
Checking the rotational direction of
the mixer motor
After being switched ON, the boiler
implements a self-test. During this, the
mixer is opened and closed again.
Changing the rotational direction of the mixer motor (if required)
gS
|
BU
~
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
Rotary capture a higher temperature. If the tem-
selector S1 perature drops, either the motor is turn-
setting ing in the wrong direction or the mixer set
is incorrectly fitted.
2
4
1. Remove the upper casing cover of
2. At plug gS, swap the cores at termi-
Mixer installation instructions
the extension kit.
Danger
An electric shock can be life-
threatening.
Before opening the boiler, dis-
connect from the mains volt-
age, for example at the fuse or
the main isolator.
nals "|" and "~".
Troubleshooting
111