Viessmann FB2A Installation And Service Instructions For Contractors page 105

Repairs
(cont.)
In the delivered condition, the mixer
motor is set up for the following mixer
arrangement (heating return from the
left).
HV
HR
KV
Changing the rotational direction of the mixer motor (if required)
Danger
An electric shock can be life-threatening.
Before opening the boiler, disconnect from the mains voltage, for example at
the fuse or the main isolator.
gS
BN
BK BU
Checking the Vitotronic 200-H (accessories)
The Vitotronic 200-H is connected to the
control unit via the LON cable. To test the
connection, carry out a subscriber check
at the boiler control unit (see page 57).
For the following mixer arrangement
(heating return from the right), change
the rotational direction.
HV
HR
KV
1. Remove the upper casing cover of
the extension kit.
2. Change the rotational direction by
switching wires BN and BK at plug
gS.
Troubleshooting
105