Viessmann VITODENS 343-F WS4A Installation And Service Instructions Manual page 104

Troubleshooting
Repairs
(cont.)
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 gas system has
cooled down by pressing "E RESET".
104
1. Pull the leads from flue gas tem-
perature sensor A..
2. Check the sensor resistance and
compare it with the curve.