EH 03 error code

What triggers it

Indoor fan speed stays too low or too high for the manual's detection time; the LED displays the failure code and the air conditioner turns off.

What to do

1. Power off, then restart the unit 2 minutes later; if the code clears, the unit is operating normally.
2. With power off, rotate the indoor fan by hand; if it does not turn easily, remove the obstruction or repair the fan assembly.
3. Check indoor fan motor wiring and correct improper connections.
4. Measure the indoor fan motor voltage from the indoor PCB; replace the indoor main PCB if the voltage is outside the manual parameters.
5. If PCB output is within the manual parameters, replace the indoor fan motor.

Reset procedure

Power off, then restart the unit 2 minutes later.

Which systems show it

• MRCOOL DIY 5th Generation single-zone 9k, 12k, 18k, 24k, and 36k D25 indoor/outdoor models listed in manual section 1.1.

Related codes

Technician scope

Indoor fan motor, PCB

Source

Next step