Communication malfunction between indoor 
and outdoor units
Communication malfunction between indoor 
and outdoor units
E1 displayed
E1 displayed
No
Power off, then restart the unit 2 
minutes later. Does a problem still 
exist?
Power off, then restart the unit 2 
minutes later. Does a problem still 
exist?
Adopt shield cable/shield 
cable earthing
Adopt shield cable/shield 
cable earthing
No
Yes
Yes
Remove interference or
add magnet ring on power 
wire
Remove interference or
add magnet ring on power 
wire
Yes
Replace the signal wire
Replace the signal wireYes
Pull out and insert back
Pull out and insert backNo
No
Replace the indoor main PCB, is the 
error resolved?
Replace the indoor main PCB, is the 
error resolved?
Yes
Replace the outdoor Main PCB.
Replace the outdoor Main PCB.
No
Is there any interference such 
as too many lamps, power 
transformers? Or is the signal 
wire too long?
Is there any interference such 
as too many lamps, power 
transformers? Or is the signal 
wire too long?
Is the signal wire a shield cable 
and is the shield cable a 
earthing?
Is the signal wire a shield cable 
and is the shield cable a 
earthing?
Is the signal wire is broken?
Is the signal wire is broken?
Are the signal wires properly 
inserted on PCB?
Are the signal wires properly 
inserted on PCB?