Viessmann VITODENS 200-W Service Instructions Manual page 77

Repairs
(cont.)
2. Test the resistance of the outside
temperature sensor across terminals
"X3.1" and "X3.2" on the disconnec-
ted plug and compare it with the
curve.
Checking the boiler water temperature sensor, the cylinder tem-
perature sensor or the flow temperature sensor for the low loss
header
A
5
X3
3. Where actual values strongly deviate
from the curve values, disconnect the
wires at the sensor and repeat test
immediately at the sensor.
4. Subject to result, replace the lead or
the outside temperature sensor.
Troubleshooting
77