64
Installation and Maintenance
Service Manual
9. Maintenance
9.1 Error Code List
No.
Malfunction
Name
Display Method of Indoor Unit
A/C status Possible Causes 
Dual-8
Code
Display
Indicator Display (during 
blinking, ON 0.5s and OFF 
0.5s)
Operation
Indicator
Cool
Indicator
Heating
Indicator
1
High 
pressure
protection of 
system
E1
During cooling and drying
operation, except indoor 
fan operates, all loads stop 
operation.
During heating operation, the 
complete unit stops.
Possible reasons: 
1. Refrigerant was superabundant; 
2. Poor heat exchange (including 
lth blockage of heat exchanger 
and bad radiating environment );
Ambient temperature is too high.
2
Low pressure
protection of 
system
E3
The Dual-8 Code Display will 
show E3 until the low pressure 
switch stop operation.
1.Low-pressure protection 
2.Low-pressure protection of 
system 
3.Low-pressure protection of 
compressor 
3
High 
discharge
temperature
protection of
compressor
E4
During cooling and drying
operation, compressor and
outdoor fan stop while indoor 
fan operates. During heating
operation, all loads stop.
Please refer to the malfunction 
analysis (discharge protection, 
overload).
4
Overcurrent
protection
E5
During cooling and drying
operation, compressor and
outdoor fan stop while indoor 
fan operates. During heating
operation, all loads stop.
1. Supply voltage is unstable;
2. Supply voltage is too low and 
load is too high;
3. Evaporator is dirty.
5
Communi-
cation
Malfunction
E6
During cooling operation,
compressor stops while 
indoor fan motor operates. 
During heating operation, the 
complete unit stops.
Refer to the corresponding 
malfunction analysis.
6
High
temperature
resistant
protection
E8
During cooling operation:
compressor will stop while 
indoor fan will operate. 
During heating operation, the 
complete unit stops.
Refer to the malfunction analysis 
(overload, high temperature 
resistant).
7
EEPROM
malfunction
EE
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
8
Limit/
decrease
frequency 
due to high
temperature 
of module
EU
All loads operate normally, 
while
operation frequency for
compressor is decreased
Discharging after the complete unit 
is de-energized for 20mins, check 
whether the thermal grease on
IPM Module of outdoor control 
panel AP1 is sufcient and whether 
the radiator is inserted tightly.
If its no use, please replace control 
panel AP1.
9
Malfunction
protection of
jumper cap
C5
Wireless remote receiver and
button are effective, but can
not dispose the related
command
1. No jumper cap insert on
mainboard.
2. Incorrect insert of jumper cap.
3. Jumper cap damaged.
4. Abnormal detecting circuit of
mainboard.