29
Installation and Maintenance
Service Manual
9. Maintenance
No.
Malfunction
Name
Display Method
A/C Status
Possible Causes
Dual-8
Code
Display
Indicator Display (during
blinking, ON 0.5s and OFF 0.5s)
Operation
Indicator
Cool
Indicator
Heat
Indicator
43
Malfunction of
phase current
detection
circuit for
compressor
U1
OFF 3S
and blink
13 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
44
Malfunction of
voltage
dropping for
DC bus-bar
U3
OFF 3S
and blink
20 times
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
45
Malfunction
of complete
units current
detection
U5
OFF 3S
and blink
13 times
During cooling and drying
operation, the compressor will
stop while indoor fan
willoperate;During heating
operating, thecomplete unit will
stop operation.
Theres circuit malfunction on
outdoor units control panel AP1,
please replace the outdoor units
control panel AP1.
46
The four-way
valve is
abnormal
U7
OFF 3S
and blink
20 times
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.
47
Zerocrossing
malfunction of
outdoor unit
U9
OFF 3S
and blink
18 times
During cooling
operation,compressor will stop
while indoor fan will operate;
during heating,the complete unit
will stop operation.
Replace outdoor control panel AP1
48
Cold air
prevention
protection
E9
Not the error code. It’s the status
code for the operation
49
Undefined
outdoor unit error
oE
Cool: compressor and outdoor
fan stops operation, while indoor
fan operates; Heat: compressor,
outdoor fan and indoor fan stop
operation.
1. Outdoor ambient temperature
exceeds the operation range of unit
(eg: less than-20oC or more than
60oC for cooling; more than 30oC
for heating);
2. Failure startup of compressor?
3. Are wires of compressor not
connected tightly?
4. Is compressor damaged?
5. Is main board damaged?
50 Defrosting
off for 0.5s
and then
blinks for
10s
Not the error code. It’s the status
code for the operation
