Checking The Boiler Water Temperature Sensor, Cylinder Temperature Sensor Or Flow Temperature Sensor For The Low Loss Header - Viessmann Vitoladens 300-W Installation And Service Instructions For Contractors

Maintenance
(cont.)
200
100
80
60
40
20
10
8
6
-20 -10 0 10 20 30
Temperature in °C
Fig. 36 Sensor type: NTC 10 k
Checking the boiler water temperature sensor, cylinder temperature sensor or flow temperature
sensor for the low loss header
A
%
Fig. 37
Ω
X3
2. Test the resistance of the outside temperature sen-
sor across terminals "X3.1" and "X3.2" on the dis-
connected plug and compare it with the curve.
3. Where actual values deviate severely from the
curve values, disconnect the wires at the sensor
and repeat test on the sensor itself.
4. Depending on the result, replace the lead or the
outside temperature sensor.
1. Boiler water temperature sensor: Disconnect
■
leads from boiler water temperature sensor
and check the resistance.
■ Cylinder temperature sensor: Disconnect plug
from the cable harness at the control unit and
check the resistance.
Flow temperature sensor: Disconnect plug "X3"
■
from the control unit and check the resistance
across terminals "X3.4" and "X3.5".
Troubleshooting
A
%
73