Gree GWHD14NK3BO Service Manual page 71

(7) Communication malfunction
Main checking points:
If the connection wire between the indoor unit and outdoor unit is connected well, if the wires inside the unit is connected well;
If the indoor mainboard or outdoor main board is broken;
Flow chart:
Communication malfunction of some
indoor units
De-energize,check the connection
wire of indoor and outdoor unit and
the wire of the eletric box is
connected correctly
Connected correctly
yes
De-energize, change the communication wire of the well-
communicated indoor unit and malfunction indoor unit,
then energize the unit and wait for 3min
The malfunction indoor unit
resumes normal
Replace the mainboard of the
malfunction indoor unit
no
yes
no
End
Reconnect according to
the wiring diagram
Replace outdoor
mainboard
Troubleshooting
Eliminate the malfunction
no
yes
69