Viessmann VITODENS 111-W Installation And Service Instructions Manual page 49

Repairs
(cont.)
Boiler water temperature sensor
A
20
10
8
6
4
2
1
0.8
0.6
0.4
10 30 50 70 90 110
Temperature in °C
1. Pull the leads off boiler water temper-
ature sensor A and check the resist-
ance.
2. Check the sensor resistance and
compare it with the curve.
3. In the case of severe deviation, drain
boiler on the heating water side and
replace the sensor.
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
49