EL 01 error code

What triggers it

The indoor unit cannot communicate with the outdoor unit.

What to do

1. Power off, then restart the unit 2 minutes later; if the error clears, the problem is solved.
2. Check indoor-to-outdoor wiring and correct or replace the wires if the connection is incorrect.
3. Measure DC voltage between N/L2 and S to determine whether the indoor or outdoor side is at fault.
4. Check indoor terminal-to-PCB and outdoor terminal-to-PCB wiring, plus AC/DC supply.
5. Check high-voltage components and the EEV coil for short circuit; replace the affected indoor PCB, outdoor PCB, IPM board, or short-circuited component as directed by the chart.

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

Comm wiring, PCBs (both), reactor

Source

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