70
15.4.19 F11 (4-way Valve Switching Failure)
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
YES
YES
YES
NO
NO, it happen in cooling/dry as well
NO
Outdoor PCB fault
No
Good
●
Reconnect CN-HOT
No
Good
●
Attach and screw the V-coil
No
continuity
(open)
Remove CN-HOT.
V-coil fault
Reverse solenoid valve faulty
Outdoor PCB fault
No supply
OK
OK
OK
When abnormality starts again
Check the indoor pipe temperature
The 4-way valve may have been damaged
●
Check connecting tubes to 4-way valve
Is the measured resistance of the indoor
Problem occurs in heating mode only?
●
Defect in indoor pipe temperature
Is 4-way solenoid valve being energised?
4-way valve not working
Check CN-HOT
Check V-coil attach to
Check valve v-coil
Measure voltage
For safety reason and to prevent component
breakdown, always switch off the power before
remove and connect the component.
OK (Depending on 4-way valve model)
YELLOW
2
1
COIL COMPLETE
CN-HOT
(WHT)
YELLOW
4 WAYS VALVE
CN-HOT
(VH9-2)
4 WAYS
VALVE
3
2
1
thermistor:
●
Plug out connector (CN-TH) from the
indoor unit PCB
●
Measure the resistance of the indoor
heat exchanger temperature thermistor
pipe temperature thermistor matches the
value specified in its characteristic chart?
or wrongly connected between discharge
and suction tube
thermistor
●
Replace the indoor pipe temperature
thermistor
(not energize)
connection
(4-way valve connector)
solenoid valve
continuity
the start of heating
supplied to CH-HOT at
●
Replace the 4-way valve
●
Replace Outdoor PCB
Measure continuity
of the coil
V-coil only
●
Replace
(4-way valve connector)
to solenoid valve
●
Replace
Outdoor PCB
* Check gas side pipe – for hot gas flow in cooling mode
