49
Installation and Maintenance
Service Manual
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
26
Compressor 
intermediate 
frequence in 
test state
P3
(during 
blinking, 
ON 
0.25s 
and OFF 
0.25s)
(during 
blinking, 
ON 
0.25s 
and OFF 
0.25s)
Showing during middle cooling or 
middle heating test
27
Overcurrent
protection of
phase 
current for 
compressor
P5
OFF 3S
and blink
15 times
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 (IPM protection, loss 
of synchronism protection and 
overcurrent protection of phase 
current for compressor.
28
Charging
malfunction 
of capacitor
PU
OFF 3S
and blink
17 times
During cooling and drying
operation, compressor will stop
while indoor fan will operate;
During heating operation, the
complete unit will stop
Refer to the part three—charging 
malfunction analysis of capacitor
29
Malfunction 
of module
temperature
sensor circuit
P7
OFF 3S
and blink
18 times
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
30
Module high
temperature
protection
P8
OFF 3S
and blink
19 times
During cooling operation,
compressor will stop while 
indoor fan will operate; 
During heating operation, the 
complete unit will stop
After the complete unit is de-
energized for 20mins, check 
whether the thermal grease on IPM 
Module  of outdoor control panel 
radiator is inserted tightly. If its no 
use, please replace control panel 
AP1.
31
Decrease
frequency 
due to high
temperature
resistant
during
heating
operation
H0
OFF 3S
and blink
10 times
All loads operate normally, 
while
operation frequency for
compressor is decreased
Refer to the malfunction analysis 
(overload, high temperature 
resistant)
32
Static 
dedusting
protection
H2
OFF 3S
and blink
twice
33
Overload
protection for
compressor
H3
OFF 3S
and blink
3 times
During cooling and drying
operation, compressor will stop
while indoor fan will operate;
During heating operation, the
complete unit will stop 
operation.
1. Wiring terminal OVC-COMP 
is loosened. In normal state, the 
resistance for this terminal should
be less than 1ohm. 
2.Refer to the malfunction analysis ( 
discharge protection, overload)