16
Installation and Maintenance
Service Manual
9. Maintenance
No. Malfunction Name
Display Method
of Indoor Unit
A/C status
Possible Causes
Dual-8 Code
Display
36 Outdoor DC fan motor
malfunction
L3
Outdoor DC fan motor malfunction lead to
compressor stop operation,
DC fan motor malfunction or system
blocked or the connector loosed
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.
47 Malfunction of
detecting plate(WIFI )
JF
Loads operate normally, while the unit can’t
be normally controlled by APP.
1. Main board of indoor unit is damaged;
2. Detection board is damaged;
3. The connection between indoor unit and
detection board is not good;
48 Refrigerant recovery
mode
Fo
Refrigerant recovery. The Serviceman
operates it for maintenance.
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-
20
o
C or more than 60
o
C for cooling; more
than 30
o
C for heating);
2. Failure startup of compressor?
3. Are wires of compressor not connected
tightly?
4. Is compressor damaged?
5. Is main board damaged?
