41
Installation and Maintenance
Service Manual
(5) 
Communication Malfunction
Disconnect power and check if 
the connection wire of indoor 
and outdoor units and the 
built-in wire of electric box are 
correctly connected. 
 
Correct connection?
Connect the wire 
properly according 
to the wiring 
diagram. 
 
Is malfunction 
eliminated?
 
Is malfunction 
eliminated?
 
Is malfunction 
eliminated?
 
Is malfunction 
eliminated?
 
Main board matches with display 
board? Main board of IDU 
matches with that of ODU? 
 
Match correctly 
according to 
product
specification. 
 
Connection of communication 
wire is damaged or not? 
 
Replace the 
connection wire. 
 
Replace the main 
board of IDU.
 
Replace the main 
board of ODU. 
End
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes Yes