61
Installation and Maintenance
Service Manual
No. Malfunction Name
Display Method of 
Indoor Unit
A/C status Possible Causes 
Dual-8 Code
Display
37 power  protection L9
compressor stop operation and Outdoor fan 
motor will stop 30s latter , 3 minutes latter fan 
motor and compressor will restart
To protect the electronical components when 
detect high power 
38
Indoor unit and outdoor 
unit doesn't match
LP compressor and Outdoor fan motor can't work  Indoor unit and outdoor unit doesn't match
39 Failure start-up LC
During cooling and drying operation, compressor 
will stop while indoor fan will operate;
During heating operation, the complete unit will 
stop operation.
Refer to the malfunction analysis
40
Cold air prevention 
protection
E9
Not the error code. It’s the status code for 
the operation.
41
Anti-freezing rotection 
for evaporator 
E2
Not the error code. It’s the status code for 
the operation.
42
Malfunction of phase 
current detection circuit 
for compressor
U1
During cooling and drying operation, compressor 
will stop while indoor fan will operate;
During heating operation, the complete unit will 
stop
Replace outdoor control panel AP1
43
Malfunction of voltage
dropping for DC bus-bar
U3
During cooling and drying operation, compressor 
will stop while indoor fan will operate;
During heating operation, the complete unit will 
stop 
Supply voltage is unstable
44
Malfunction of complete 
unit's current detection
U5
During cooling and drying operation, the 
compressor will stop while indoor fan will operate; 
During heating operating, the complete unit will 
stop operation.
There's circuit malfunction on outdoor unit control 
panel AP1, please replace the outdoor unit 
control panel AP1.
45
The four-way valve is
abnormal
U7
If this malfunction occurs during heating 
operation, the complete unit will stop operation.
1.Supply voltage is lower than AC175V;
2.Wiring terminal 4V is loosened or broken;
3.4V is damaged, please replace 4V.
46
Malfunction of zero-cross 
detection circuit
U8 The complete unit stops
1.Power supply is abnormal;
2.Detection circuit of indoor control mainboard is 
abnormal.