Temperature Sensor - Viessmann Vitoladens 300-C Service Instructions Manual

Repairs
(cont.)
Checking the boiler water temperature sensor or the cylinder

temperature sensor

5
20
10
8
6
4
2
1
0.8
0.6
0.4
10 30 50 70 90 110
Temperature in °C
1. ■ Boiler water temperature sensor:
Pull the leads from boiler water
temperature sensor A and check
the resistance.
■ Cylinder temperature sensor: Pull
plug % from the cable harness at
the control unit and check the
resistance.
2. Check the sensor resistance and
compare the actual values with the
curve.
3. Replace the sensor in case of severe
deviation.
Danger
The boiler water temperature
sensor is immersed in the
heating water (risk of scald-
ing).
Drain the boiler before replac-
ing the sensor.
Troubleshooting
69