Gree U-MATCH Series Service Manual page 89

U-Match Series DC Inverter Service Manual
 E4 Discharge Protection
 E6 Communication Malfunction
Communication
malfunction
Check if the
communication wire between
indoor unit and outdoor unit is
connected well
Yes
Check if there is
open circuit in the communication
wire between indoor unit and
outdoor unit
No
Check if the
outdoor unit is energized
Yes
Replace the mainboard
No
Reconnect the
communication
wire
Yes
Replace the
communication
wire
No Energize the
outdoor unit
86