Check Flue Gas Temperature Sensor - Viessmann VITODENS 200-W WB2B Start-Up/Service Instructions

Corrective Action
40
20
10
8
6
4
2
1
0.8
0.6
0.4
0.2
50 86 122 158 194 230
68 104 140 176 212 248
70
10 30 50
80
20 40 60
Boiler water temperature in ºF/ºC
A
Fig. 22
A
Flue gas temperature sensor
(continued)
Check boiler temperature sensor, tank temperature sensor or
supply temperature sensor of the low-loss header (continued)
2. Check the sensor resistance and
compare the actual values with the
curve in the chart.
3. If the value measured differs
significantly, replace sensor.
90 110
100 120

Check flue gas temperature sensor

When exceeding the maximum permissible flue gas temperature value, the flue
gas temperature sensor locks the appliance. Unlock the appliance by pressing
" RESET" after the vent system has cooled down.
20
10
8
6
4
2
1
0.8
0.6
0.4
50 86 122 158 194230
10 30 50 70 90 110
Temperature in ºF/ºC
Troubleshooting
WARNING
The boiler temperature sensor is
immersed in the heating water (risk
of scalding). Drain the boiler before
replacing the sensor.
1. Remove cables from flue gas
temperature sensor A.
2. Check the sensor resistance and
compare the actual values with the
curve in the chart.
3. Replace sensor in case of severe
deviation.
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