Panasonic WH-ADC0309H3E Service Manual page 168

17.5.19 Tank Temperature Sensor Abnormality (H72)
Malfunction Decision Conditions:
When tank connection is set to ON, the temperatures detected by the tank temperature sensor are used to
determine sensor error.
Malfunction Caused:
1 Faulty connector connection.
2 Faulty sensor.
3 Faulty indoor unit PCB (main).
Abnormality Judgment:
Continue for 5 seconds.
Troubleshooting:
Is the abnormality happened during
tank connection set to ON?
Yes
Check the terminal board assembly no. 15 and
no.16, and CN-TH2 connector connections:
- Turn OFF the power.
- Check the connector connections.
Tank Sensor Characteristics
11
10
9
8
7
6
5
4
3
2
1
0
-10 0
No
Check the tank temperature sensor:
- Plug out connector from the indoor unit PCB (main).
- Measure the resistance of the tank temperature
sensor.
10 20 30 40 50
Temperature (°C)
For safety reason and to prevent component breakdown,
always switch off the power before remove and connect the component.
- Defect in indoor unit PCB (main).
- Replace the indoor unit PCB (main).
Is the terminal board assembly
no. 15 and no. 16, and CN-TH2
connector connections normal?
Yes
Is the measured resistance of the
tank temperature sensor matches
the value specified in its
characteristic chart?
Yes
168
No
- Connector poor contact.
- Correct the connection.
- Defect in tank temperature sensor.
No
- Replace the tank temperature
sensor.
- Defect in indoor unit PCB (main).
- Replace the indoor unit PCB (main).