35
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
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 units
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.
Theres circuit malfunction on outdoor
units control panel AP1, please replace
the outdoor units 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
Frequency
limiting
(power)
47
Compressor is
open-circuited
48
The temperature
for turning on the
unit is reached
49
Frequency
limiting (module
temperature)
50
Water overflow
protection
E9
The complete unit stops
If the condition of full of water is
detected for 8s, water overflow
protection will be enabled and wired
controller will display E9 and give
an alarm; in each mode, if system
enters water overflow protection,
indoor units will shut down except
the water pump and alarm. The
capacity output of outdoor units
should be adjusted correspondingly.
