Viessmann Vitoligno 300-C Installation And Service Instructions Manual page 114

Maintenance
Sensors
(cont.)
Check sensors
Flue gas temperature sensor
1.75
1.25
0.75
A 50
0
Temperature in °C
Fig. 55
Data point shown: Resistance of 1.1 k
A
perature of 25 °C
Further sensors
1.20
1.15
1.10
1.05
1.00
0.95
0.90
0.85
-30 -20 -10
Temperature in °C
Fig. 56
1. Pull out corresponding plug.
2. Check the sensor resistance at the disconnected
plug.
Lambda probe
The Lambda probe measures the residual oxygen con-
tent in the flue gas.
Make of Lambda probe: NTK wideband probe
Checking the Lambda probe
1. Check the Lambda probe for dirt and damage. See
page 67.
2. Check the connecting cable for damage.
114
150
100
at a tem-
Ω
0 10 20 30 40
200 250
50
3. Compare the result with the actual temperature (for
scanning, see chapter "Diagnosis").
In the case of severe deviation, check sensor
installation and replace the sensor if necessary.