Communication Malfunction - Gree GWH18UC-K3DNA1A/I Service Manual

The AP1 voltage
detection circuit Y
is at fault
If the fault is eliminated?
N
Y
Did the equipment operate
normally before the failure
Y
Check wiring inside of
the indoor and outdoor
units
Are wires broken?
N
Check the communication
circuit of the outdoor unit
The communication
Y
circuit is abnormal
N
N
Replace the main board
of the indoor unit
Start
occurs?
Y
N
Replace the main board
AP1 of the outdoor unit
If the fault is eliminated?
Y
End
N
Check the wiring of the indoor and
outdoor units with reference to the
wiring diagram
Is the connection right?
N
Correctly connect the
corresponding wires for
the indoor and outdoor
units with reference to
the wiring diagram
If the fault is eliminated?
Y