Viessmann VITODENS 200-W Service Instructions Manual page 108

Troubleshooting
Repair
(cont.)
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
Checking the temperature limiter
Check if the burner control unit cannot be reset after a fault shutdown, although the
boiler water temperature is below approx. 75 °C.
A
1. Pull the leads from temperature lim-
iter A.
108
2. Check the sensor resistance and
compare the actual values with the
curve.
3. Replace the sensor in the 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.
2. Check the continuity of the tempera-
ture limiter with a multimeter.