Viessmann Vitocrossal 300 Service Instructions For Contractors page 108

Troubleshooting
Repairs
(cont.)
20
10
8
6
4
2
1
0.8
0.6
0.4
10 30 50 70 90 110
Temperature in °C
Checking the flue gas temperature sensor
The flue gas temperature sensor locks out the boiler when the permissible flue gas
temperature is exceeded. Reset the interlock after the flue system has cooled down
by pressing reset button R.
108
3. Replace the sensor in the case of
severe deviation.
1. Pull the leads from flue gas tempera-
ture sensor A.