If the sampling voltage is not 5V, the LED displays the failure.
Yes
No
Yes
No
Temperature protection of the
compressor top.
Check the air ow system of the
indoor and outdoor units.
Clear up the air inlet and outlet or the indoor
and outdoor heat exchanger.
Power OFF, then restart
the unit minutes later.
Check whether the
compressor top temperature
is higher than 212 °F (100° C).
Check the refrigerant
volume charge.
Refrigerant system is blocked, for
ex. capillary or welded point of pipes.
Check the overload protector
of the wiring connection.
Correct the connection.
Measure the resistance
between the two OLP ports.
It is zero (0)?
Replace the OLP.
Replace the outdoor main PCB.
Recharge the correct
refrigerant volume.