Viessmann VITODENS 242-F Installation And Service Instructions Manual page 142

Troubleshooting
Repair
(cont.)
aVG %
100
10
1
0.1
0 20 25
Temperature in °C
A Collector temperature sensor (sen-
sor type: NTC 20 kΩ)
1. ■ Cylinder temperature sensor
Remove plug % from solar control
module A and check the resist-
ance.
■ Collector temperature sensor
Disconnect the lead from terminal
box B and check the resistance.
142
&
40 60
B
80 100 120
B Cylinder temperature sensor (sen-
sor type: NTC 10 kΩ)
2. Compare the sensor resistance with
the curve.
3. In the case of severe deviation,
replace the sensor.
A
140