AE-X15PU
3 – 14
Indoor and 
outdoor 
units do not 
operate.
5-time O O O O O Timer (Orange) 5 0 Outdoor unit 
thermistor 
open-circuit
Heat exchanger 
thermistor open 
circuit error
1) Check connector of 
outdoor unit thermistor 
for secure installa ion.
2) Measure resistance of 
outdoor  hermistors 
3) Check the lead wires 
of  hermistors on the  
outdoor unit control  
PCB for open-circuit.
4) 1) 2) 3):Normal
1) Correct the installa-
ion
2) Replace the outdoor 
unit thermistor 
assembly.
3) Replace the outdoor 
unit thermistor 
assembly.
4) Replace the outdoor 
unit control PWB 
assembly.
O O Operation (
Green
)
Plasmacluster (Blue)
O O O O O Timer (Orange) 1 Outdoor temperature 
thermistor open 
circuit error
O O Operation (
Green
)
O Plasmacluster (Blue)
O O O O O Timer (Orange) 2 Suction thermistor 
open circuit error
O O Operation (
Green
)
O Plasmacluster (Blue)
O O O O O Timer (Orange) 3 Suction thermistor 
 open circuit error
O O Operation (
Green
)
O O Plasmacluster (Blue)
O O O O O Timer (Orange) 4 Discharge thermistor 
open circuit error
O O Operation (
Green
)
O Plasmacluster (Blue)
O O O O O Timer (Orange) 5 Heat sink thermistor 
open circuit error
O O Operation (
Green
)
O O Plasmacluster (Blue)
Problem 
symptom
Outdoor 
unit 
indication 
(LED1)
Indoor unit
Malfunction 
No.*
Content of diagnosis Check point Action
→
Lamp Main Sub Main Sub
Indoor and 
outdoor 
units do not 
operate.
6-time O O O O O Timer (Orange) 6 0 Outdoor unit
DC Current
DC over current 
error
Go to “DC Over Current Error (6-0 error)”.
O O Operation (
Green
)
Plasmacluster (Blue)
O O O O O Timer (Orange) 1 IPM pin level error Check the IPM is attached 
correctly to the outdoor unit 
IPM PWB.
Replace the outdoor 
unit IPM PWB 
assembly.
O O Operation (
Green
)
O Plasmacluster (Blue)
Indoor and 
outdoor 
units do not 
operate.
7-time O O O O O Timer (Orange) 7 0 Outdoor unit
AC Current
AC over current error 1) Ensure unobstructed air 
unit air outlet.
2) Check the outdoor unit 
fan motor.
1) Ensure unobstructed 
outdoor unit air 
outlet.
2) Check the outdoor 
unit fan motor.
O O O Operation (
Green
)
Plasmacluster (Blue)
O O O O O Timer (Orange) 1 AC current error 
when OFF
1) IPM con inuity check 1) Replace the outdoor 
IPM PWB
O O O Operation (
Green
)
O Plasmacluster (Blue)
O O O O O Timer (Orange) 2 AC maximum current 
error
1) Ensure unobstructed air 
unit air outlet.
2) Check the outdoor unit 
fan motor.
1) Ensure unobstructed 
outdoor unit air 
outlet.
2) Check the outdoor 
unit fan motor.
O O O Operation (
Green
)
O Plasmacluster (Blue)
O O O O O Timer (Orange) 3 AC current 
1) Replace the outdoor unit 
control PCB assembly.
amount of refrigerant.
3) Correct refrigerant clogs. 
(Stop valve, pipe, 
expansion valve)
1) Replace the outdoor 
unit control PCB 
assembly.
amount of refriger-
ant.
3) Correct refrigerant 
clogs. (Stop valve, 
pipe, expansion 
valve)
O O O Operation (
Green
)
O O Plasmacluster (Blue)
Indoor and 
outdoor 
units do not 
operate.
8-time O O O O O Timer (Orange) 8 0 Abnormal 
wire check
Abnormal wire check 
error
1) Check the expansion 
valve.  
2) Are four expansion 
valves connected by 
mistake.
3) Check the wiring 
between units.
1) Replace the outdoor 
control board 
assembly.
2) Reattach
3) Check the wiring 
between units.
O Operation (
Green
)
Plasmacluster (Blue)