When outdoor fan speed keeps too low (300RPM) or too 
high(2400RPM) for certain time, the unit will stop and the LED will 
display the failure.  
Power off, then restart the 
unit 3 minutes later. Is it still 
displaying the error code?
Power off, then restart the 
unit 3 minutes later. Is it still 
displaying the error code?
Shut off the power supply, 
rotate  the  fan  by  hand.  Does 
it rotate properly? 
Shut off the power supply, 
rotate  the  fan  by  hand.  Does 
it rotate properly? 
The unit operates normally.
The unit operates normally.
Find out the cause and 
have it solved. For 
example,  whether the fan 
is blocked or the screws 
which fix the fan are 
tighten.
Find out the cause and 
have it solved. For 
example,  whether the fan 
is blocked or the screws 
which fix the fan are 
tighten.
Check the wiring of fan 
motor. Are all the 
connections good?
Check the wiring of fan 
motor. Are all the 
connections good?
No
Yes
No
Correct the connections.
Correct the connections.No
Replace the fan motor
Replace the fan motor
Yes
Yes
Replace the main PCB
Replace the main PCBNo
Check whether the main PCB 
is normal through index 1?
Check whether the main PCB 
is normal through index 1?
Yes
No