Panasonic WH-ADF0309J3E5CM Service Manual page 279

25.2.32 Four Way Valve Abnormality (F11 / L18 / F25)
Malfunction Decision Conditions

When indoor heat exchanger is cold during heating (except deice) or when indoor heat exchanger is hot during
cooling and compressor operating, the 4-way valve is detected as malfunction.
Malfunction Caused

Indoor heat exchanger (pipe) thermistor

4-way valve malfunction
Troubleshooting
When abnormality starts again
Check the indoor pipe temperature
thermistor:
● Plug out connector (CN-TH) from the
indoor unit PCB
● Measure the resistance of the indoor
heat exchanger temperature thermistor
Is the measured resistance of the indoor
pipe temperature thermistor matches the
value specified in its characteristic chart?
YES
Problem occurs in heating mode only?
NO, it happen in cooling/dry as well
Is 4-way solenoid valve being energised?
NO
The 4-way valve may have been damaged
or wrongly connected between discharge
and suction tube
● Check connecting tubes to 4-way valve
* Check gas side pipe – for hot gas flow in cooling mode
For safety reason and to prevent component
breakdown, always switch off the power
Caution
before remove and connect the component.
● Defect in indoor pipe temperature
NO
thermistor
● Replace the indoor pipe temperature
thermistor
YES
YES
4-way valve not working
Outdoor PCB fault
(not energize)
● Replace
Outdoor PCB
Check CN-HOT
connection
(4-way valve connector)
Check V-coil attach to
solenoid valve
Check valve v-coil
continuity
Measure voltage
supplied to CH-HOT at
the start of heating
Outdoor PCB fault
●
279
4 WAYS VALVE
No
Good
OK
No
Good
No
OK
continuity
(open)
Remove CN-HOT.
Measure continuity
of the coil
OK
OK (Depending on 4-way valve model)
No supply
Replace Outdoor PCB
1
YELLOW
CN-HOT
(WHT)
YELLOW
2
COIL COMPLETE
● Reconnect CN-HOT
(4-way valve connector)
● Attach and screw the V-coil
to solenoid valve
V-coil fault
● Replace
CN-HOT
V-coil only (VH9-2)
1 2 3
Reverse solenoid valve faulty
● Replace the 4-way valve
4 WAYS
VALVE