29
Installation and Maintenance
Service Manual
9. Maintenance
9.1 Error Code
No.
Malfunction
Name
Display Method
of Indoor Unit
(Error Code)
A/C Status
Possible Causes(For specific maintenance
method, please refer to the following procedure of
troubleshooting)
1
Indoor ambient
temperature
sensor is open/
short- circuited
F1
The unit will stop operation as it
reaches the temperature point. During
cooling and drying operation, except
indoor fan operates, other loads
（
such
as compressor, outdoor fan, 4-way
valve
）
stop operation; During heating
operation, the complete unit stops
operation.
1. The wiring terminal between indoor ambient temperature
sensor and controller is loosened or poorly contacted;
2. There’s short circuit due to trip-over of the parts on
controller;
3.Indoor ambient temperature sensor is damaged (Please
check it by referring to the resistance table for temperature
sensor)
4. Main board is broken.
2
Indoor
evaporator
temperature
sensor is open/
short-circuited
F2
The unit will stop operation as it
reaches the temperature point. During
cooling and drying operation, except
indoor fan operates, other loads stop
operation; During heating operation,
the complete unit stops operation.
1. The wiring terminal between indoor evaporator
temperature sensor and controller is loosened or poorly
contacted;
2. There’s short circuit due to the trip-over of the parts on
controller;
3.Indoor evaporator temperature sensor is damaged (Please
check it by referring to the resistance table for temperature
sensor)
4. Main board is broken.
3
Blocked
protection of
IDU fan motor
H6
IDU fan, ODU fan, compressor and
electric heat tube stop operation.
Horizontal louver stops at the current
position.
1. The feedback terminal of PG motor is not connected
tightly.
2. The control terminal of PG motor is not connected tightly.
3. Fan blade rotates unsmoothly.
4. Malfunction of motor
5. Main board is broken.
4
Malfunction
protection of
jumper cap
C5
Operation of remote controller or
control panel is available, but the unit
won’t act.
1. There’s not jumper cap on the main board.
2. Jumper cap is not inserted properly and tightly.
3. Jumper cap is damaged.
4. Controller is damaged.
5
Zero-crossing
inspection
circuit
malfunction
of the IDU fan
motor
U8
Operation of remote controller or
control panel is available, but the unit
won’t act.
1. Quick de-energization and energization. Wrong
judgement by the controller because the electric-
discharging of capacitor is slow.
2. Zero-crossing inspection circuit of main board for
controller is abnormal.
6
Outdoor
ambient
temperature
sensor is open/
short-circuited
F3
The unit will stop operation as it
reaches the temperature point.
During cooling and drying operation,
compressor stops and indoor fan
operates; During heating operation,
the complete unit stops operation.
1. The wiring terminal between outdoor ambient temperature
sensor and controller is loosened or poorly contacted;
2. There’s short circuit due to the trip-over of the parts on
controller;
3.Outdoor ambient temperature sensor is damaged (Please
check it by referring to the resistance table for temperature
sensor)
4. Main board is broken.
7
Outdoor
condenser
temperature
sensor is open/
short-circuited
F4
The unit will stop operation as it
reaches the temperature point.
During cooling and drying operation,
compressor stops and indoor fan
operates; During heating operation,
the complete unit stops operation.
1. The wiring terminal between outdoor condenser
temperature sensor and controller is loosened or poorly
contacted;
2. There’s short circuit due to the trip-over of the parts on
controller;
3.Outdoor condenser temperature sensor is damaged
(Please check it by referring to the resistance table for
temperature sensor)
4. Main board is broken.
