34
Installation and Maintenance
Service Manual
Possible Causes  Discriminating Method (Air conditioner Status) Troubleshooting 
Set temperature is improper Observe the set temperature on remote controller  Adjust the set temperature
Rotation speed of the IDU fan 
motor is set too low
Small wind blow  Set the fan speed at high or medium 
Filter of indoor unit is blocked  Check the lter to see it's blocked  Clean the lter 
Installation position for indoor unit 
and outdoor unit is improper 
Check whether the installation postion is proper 
according to installation requirement for air 
conditioner 
Adjust the installation position, and install the 
rainproof and sunproof for outdoor unit
Refrigerant is leaking 
Discharged air temperature during cooling is 
higher than normal discharged wind temperature; 
Discharged air temperature during heating is 
lower than normal discharged wind temperature; 
Unit's pressure is much lower than regulated 
range 
Find out the leakage causes and deal with it. 
Add refrigerant. 
Malfunction of 4-way valve  Blow cold wind during heating  Replace the 4-way valve 
Malfunction of capillary
Discharged air temperature during cooling is 
higher than normal discharged wind temperature; 
Discharged air temperature during heating is 
lower than normal discharged wind temperature; 
Unit't pressure is much lower than regulated 
range. If refrigerant isn’t leaking, part of capillary 
is blocked 
Replace the capillary
Flow volume of valve is 
insufcient 
The pressure of valves is much lower than that 
stated in the specication
Open the valve completely 
Malfunction of horizontal louver  Horizontal louver can’t swing 
Refer to point 3 of maintenance method for 
details 
Malfunction of the IDU fan motor  The IDU fan motor can’t operate 
Refer to troubleshooting for H6 for maintenance 
method in details 
Malfunction of the ODU fan motor The ODU fan motor can't operate 
Refer to point 4 of maintenance method for 
details 
Malfunction of compressor  Compressor can't operate 
Refer to point 5 of maintenance method for 
details 
8.3 Maintenance Method for Normal Malfunction
1. Air Conditioner Can't be Started Up
2. Poor Cooling (Heating) for Air Conditioner 
3. Horizontal Louver Can't Swing
Possible Causes  Discriminating Method (Air conditioner Status) Troubleshooting 
No power supply, or poor 
connection for power plug
After energization, operation indicator isn’t bright 
and the buzzer can't give out sound 
Conrm whether it's due to power failure. If yes, 
wait for power recovery. If not, check power 
supply circuit and make sure the power plug is 
connected well. 
Wrong wire connection between 
indoor unit and outdoor unit, 
or poor connection for wiring 
terminals 
Under normal power supply circumstances, 
operation indicator isn't bright after energization
Check the circuit according to circuit diagram 
and connect wires correctly. Make sure all 
wiring terminals are connected rmly
Electric leakage for air conditioner
After energization, room circuit breaker trips off at 
once
Make sure the air conditioner is grounded 
reliably
Make sure wires of air conditioner is connected 
correctly
Check the wiring inside air conditioner. Check 
whether the insulation layer of power cord is 
damaged; if yes, place the power cord.
Model  selection  for air  switch  is 
improper
After energization, air switch trips off Select proper air switch
Malfunction of remote controller 
After energization, operation indicator is bright, 
while no display on remote controller or buttons 
have no action. 
Replace batteries for remote controller
Repair or replace remote controller
Possible Causes  Discriminating Method (Air conditioner Status) Troubleshooting 
Wrong wire connection, or poor 
connection 
Check the wiring status according to circuit 
diagram 
Connect wires according to wiring diagram to 
make sure all wiring terminals are connected 
rmly
Stepping motor is damaged  Stepping motor can't operate  Repair or replace stepping motor 
Main board is damaged 
Others are all normal, while horizontal louver 
can't operate 
Replace the main board with the same model