Viessmann VITODENS 242-F Installation And Service Instructions Manual page 150

Troubleshooting
Repair
(cont.)
Check flow temperature sensor
Pressure drop curve
20
10
8
6
4
2
1
0.8
0.6
0.4
10 30 50 70 90 110
Temperature in °C
Sensor type: NTC 10 kΩ
1. Disconnect plug ? (flow tempera-
ture sensor).
Checking the Vitotronic 200-H (accessory)
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 82).
150
2. Check the sensor resistance and
compare it with the curve.
Replace the sensor in the case of
severe deviation.