23
Installation and Maintenance
Service Manual
7. Communication malfunction E6
Main detection points:
● Check if the connection wire and the built-in wiring of indoor and outdoor unit are connected well and without damage;
● If the communication circuit of indoor mainboard is damaged? If the communication circuit of outdoor mainboard (AP1) is damaged?
Malfunction diagnosis process:
Note: method for checking the communication circuit of outdoor unit: cut off the communication wires of indoor/outdoor unit, and
then measure the voltage between COM and N of the control board of outdoor unit (DC notch, about 56V)
Start
Y
Y
Y
Y
Y
Y
Y
N
N
N
N
N
N
If the unit is operation
normal before
malfunction
Check connection
wire of indoor and
outdoor unit with
circuit diagram
Connection
correct?
Check connection
wire of indoor and
outdoor unit with
circuit diagram
If the malfunction
is removed?
Problem of
communication
circuit
Check communication
circuit of outdoor unit
Replace indoor
board
Replace outdoor
mainboardAP11
If the
malfunction is
removed?
End
If the wiring is
damaged?
Check built-in wiring
of indoor and
outdoor unit
Malfunction of
circuit is
detected with
control board
AP1 voltage
If the malfunction
is removed?
9. Maintenance
