Viessmann Vitodens 300 Service Instructions Manual page 86

Troubleshooting
Repairs
(cont.)
86
2. Test the resistance of the outside
temperature sensor across term-
inals X3.1 and X3.2 on the discon-
nected plug and compare with the
curve.
3. Where actual values strongly devi-
ate from the curve values, discon-
nect the wires at the sensor and
repeat test directly at the sensor.
4. Depending on the result, replace
cable or outside temperature sen-
sor.