Panasonic WH-ADC0916G9E8, Service Manual, Page: 134 / 205

134
17.5.26 Four Way Valve Abnormality (F25)
Malfunction Decision Conditions:
1 During heating operation, when the indoor pipe temperature of thermostat ON indoor unit < 0°C.
2 During cooling operation, when the indoor pipe temperature of thermostat ON indoor unit > 45°C.
Malfunction Caused:
1 Faulty sensor.
2 Faulty connector connection.
3 Faulty outdoor unit PCB (noise filter/main).
4 Faulty four way valve.
Abnormality Judgment:
Continue 4 times in 30 minutes.
Troubleshooting:
For safety reason and to prevent component breakdown,
always switch off the power before remove and connect the component.
Check the indoor pipe
temperature sensor.
Four way valve coil
disconnected (loose)?
Is the harness out of the
CN-HOT connector?
Check the continuity of the
four way valve coil.
Is the voltage supply to four
way valve 230 Vac?
Disconnect the harness from the
CN-HOT connector. Resistance
between harness about 1.52 kohm?
Measure AC voltage supply to
CN-HOT (pin 1 & 3) during heating
operation.
Does it conform to the
sensor characteristic chart?
Is F25 occur during heating
operation?
Is the four way valve coil energize
during cooling operation?
Replace the indoor pipe
temperature sensor.
Replace the outdoor unit
PCB (noise filter/main).
Replace the four way valve.
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Correct the four way valve
coil.
Reconnect the harness.
Replace the four way valve
coil.
Replace the outdoor unit
PCB (noise filter/main).
Replace the four way valve.
1 2 3
CN-HOT
(VH3-2)
4 WAYS
VALVE