140
Checking the temperature sensors
Outside temperature sensor
Fig. 90
100
10
-20 -10 0
10 20 30
Temperature in °C
6
8
20
40
60
80
200
Resistance
in kΩ
Fig. 91
Sensor type: NTC 10 k
Ω
1.
Strip plug
!
on heat management unit.
2.
Test the resistance of the outside temperature sen-
sor at the disconnected plug and compare it with
the curve.
3.
In the event of severe deviation from the curve,
disconnect the wires at the sensor and repeat the
test on the sensor itself.
4.
Depending on the test result, replace the lead or
the outside temperature sensor.
Temperature sensors inside Vitovalor PT2
For the electrical connection of the temperature sen-
sors, see connection and wiring diagrams from
page 155.
Danger
The temperature sensors are immersed in the
heating water (risk of scalding).
Drain the boiler before replacing the sensor. See
page 137.
10
1
10 30 50 70 90 110
Temperature in °C
0.4
0.6
0.8
2
4
6
8
20
Resistance
in kΩ
Fig. 92
Sensor type: NTC 10 k
Ω
1.
Pull plug and measure the sensor resistance. See
connection and wiring diagrams from page 155.
2.
Compare the sensor resistance with the curve.
3.
In the event of severe deviation replace the sensor.
Checking the flue gas temperature sensor
The flue gas temperature sensor locks out the boiler if
the permissible flue gas temperature is exceeded.
Unlock the appliance once the flue system has cooled
down (see operating instructions).
Troubleshooting
Repairs
(cont.)
5853335
Diagnosis
