Viessmann VITOTRONIC 300 GW2 Installation And Service Instructions Manual page 137

Wiring diagram
(continued)
Low-voltage motherboard (continued)
Outdoor temperature
!
sensor/radio clock receiver
(accessory)
Boiler temperature sensor
§
DHW tank temperature
%
sensor/2nd DHW tank
temperature sensor with DHW
tank loading system (accessory)
aG Flue gas temperature sensor
(accessory)
aJA Temperature sensor of
Therm-Control
or
temperature sensor T1
aJB Temperature sensor T2
aVD Connection of external
equipment
aVG KM BUS participant (accessory)
aVH Connection of external
equipment
LON Connecting cable for data
transfer between the control
units (accessory)
Additional information
S3 Emissions test switch "S"
V1 Fault indicator (red)
V2 Operating status indicator (green)
137