Owner's Manual

mrcool.com
Note: For certain models, the outdoor PCB cannot
be removed separately. In this case, the outdoor
electric control box should be replaced as a whole.
Page 46
10.3 Error Code: EH 02 (Zero crossing detection error diagnosis and solution)
Description: When PCB does not receive zero crossing signal feedback for 4 minutes or the zero crossing
signal time.
Recommended parts to prepare:
•
Connection wires
•
PCB
Troubleshooting and repair:
Check the connections
and the power supply.
Correct the connections. Turn on the unit
when the power supply is shown to be good.
NO
Indoor main PCB is defective.
Replace indoor main PCB.
YES
Is it normal?
10.4 Error Code(s): EH 03 / EC 07 (Fan speed is operating outside of normal range diagnosis and solution)
Description: When indoor/outdoor fan speed is too low or too high for a certain amount of time, the LED displays
the failure code and the A/C turns off.
Recommended parts to prepare:
• Connection wires
•
Fan assembly
•
Fan motor
•
PCB
Troubleshooting and repair:
YES
Power off, then restart unit after 2 minutes
Is it within normal parameters?
Replace the fan motor
Does the problem
remain?
The unit is operating normally. NO
Shut off the power supply &
rotate the fan by hand.
YES
Does it turn easily?
Find the cause of the problem and resolve it. NO
Check the wiring of fan motor.
YES
Is it properly wired?
Ensure proper connections
Measure the voltage for
the fan motor from the PCB.
YES
Replace the PCB.NO
NO
Disclaimer: The error codes and descriptions are for reference only. If your system displays any of
these codes contact a qualified technician to investigate the matter further.