LG Refrigerator Error Code Er CO
The main board and the display board have stopped talking to each other. A full power reset is the only owner-level step; if the code comes back, a technician needs to test the boards and the door harness.
Also shown as: E CO
Common causes
- Loose or damaged wiring harness between the boards, often where it passes through the door
- Display control board failed
- Main power control board failed
What to check, in order
- Unplug the refrigerator for 5 to 10 minutes so both boards fully reset, then restore power
- Use the refrigerator normally for a day and note whether the code returns, and whether it tends to appear after the doors have been opened and closed a lot; tell the technician, as that points to the door harness
- If the code returns after the reset, there are no further owner-level steps: a technician needs to test the display board, the main board and the harness between them
Clear the code and test
- Fix what the checks above found first. Clearing the code without fixing the cause only brings it back.
- Plug the appliance back in and restore its water supply if it has one.
- Run the shortest programme and watch the point where the code appeared before.
- If the programme finishes with no code, the fault is cleared. If the code returns, write it down before calling a technician — it speeds up the diagnosis.
When to call a professional
This code usually points to a faulty part, wiring or the control board on a LG refrigerator. Run the checks above to rule out the simple causes, then book a technician — and book one straight away if any of these apply:
- The code comes back after you have run the checks and a test cycle.
- You smell burning, see sparks or scorch marks, or the breaker trips.
- Water is leaking and you cannot stop it at the tap.
- The fix needs panels opened beyond what your manual describes, or a part tested with a meter, and you are not set up for that.
When you call, give the brand, the code Er CO, your model number (on a label inside the door or on the back) and the checks you already ran. It shortens the visit.
Repair or replace?
This fault is in professional territory: the fix usually means a major part or board-level work, and the labour adds up. If your machine is already well into its service life, get the repair quote first, then compare it with the price of a current equivalent model before you decide. Paying a large share of a new machine's price to repair an old one is rarely the better deal; replacing a machine over one cheap fault is wasteful too.
Parts that may be involved
Display control boardMain power control boardWiring harness
Parts are model-specific. Find your model number first — usually on a label inside the door, on the door frame or on the back — and match the part to that number before ordering.
Questions people ask about Er CO
What does Er CO mean on a LG refrigerator?
Er CO means: Communication error between the main control board and the display board. The main board and the display board have stopped talking to each other. A full power reset is the only owner-level step; if the code comes back, a technician needs to test the boards and the door harness.
Can I fix LG Er CO myself?
Only the preliminary checks. Code Er CO usually means a part, wiring or the control board has failed, which is a technician job. Run the checks to rule out simple causes before you book.
How do I clear LG Er CO?
Fix the cause first — clearing the code on its own brings it straight back. Then restore power and water, run the shortest programme, and watch the stage where the code appeared. If the programme finishes with no code, it is cleared.
Sources checked
- LG Help Library: washing machine error codes
- PartsTown Resource Center: LG washing machine troubleshooting codes
The meaning and checks for this code were checked against the sources above in November 2026. Codes vary by model and region; if your manual lists a different meaning for your exact model, follow the manual.