When indoor fan speed keeps too low (300RPM) for certain time, 
the unit will stop and the LED will display the failure. 
Shut off the power supply 
and turn it on 5 seconds 
later. Is it still displaying 
the error code?
Shut off the power supply, 
rotate  the  fan  by  hand. 
Does it rotate properly?
The unit operates normally.
Find out the cause and 
have it solved. For 
example, check 
whether the fan is 
blocked or the bearing 
is broken?
Check the wires of fan 
motor. Are all the 
connections good?
No
Yes
No
Correct the connections.No
Yes
Check whether the main PCB is 
normal through index 2?
Yes
Yes
Check whether the fan 
motor is  normal through 
index 1?
Yes
Replace the fan 
motor
Replace the 
main  PCB. 
The 
malfunction is 
solved?
No
No
If the 
malfunction is 
still existing, 
replace the 
main PCB
No