Viessmann VITOTRONIC 300 GW2 Installation And Service Instructions Manual page 29

Connection of the flue gas temperature sensor (VD2/VD2A/CT3 only)
1020
980
940
900
860
820
780
740
700
660
620
580
540
500
120 160 200 240 280
0 40 80
104 176 248 360 392 464 536
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Flue gas temperature in °C / °F
Installation
The sensor measures the flue gas
temperature and monitors the
selected limit value.
Electrical connection
The sensor is inserted in socket
"15" on the boiler control.
Check flue gas temperature sensor
1. Disconnect plug aG in the
terminal compartment .
2. Measure resistance of sensor
at terminals "1" and "2" of the
plug.
Flue gas Resistance
in 
temperature
in °C / °F
180 / 176 650
160 / 320 800
200 / 392 880
3. Compare the value measured
with the actual temperature If
the value differs significantly,
check installation and, if
necessary, replace sensor.
Technical data
Degree of
protection: IP 60
Ambient temperature
During operation:
0 to + 600°C
32 to + 1112°F
During storage and transport:
-20 to + 70°C
-4 to + 158°F
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