LG Mini Split CH26 Error Code: Compressor Starting Failure (Meaning, Causes, Fixes)
What the code means
LG's R410A air conditioner service manual lists error 26 as "Inverter compressor starting failure Error", with the error point "starting failure because of compressor abnormality" (the outdoor unit error table calls it the first start failure of the outdoor unit inverter compressor). LG Canada's error chart describes code 26 as the inverter compressor having seized up or not providing rotation; on North American indoor units without a display, the same code is shown as a blinking LED pattern. LG USA says CH21, CH23, CH26, CH29 and E9 point to the outdoor unit compressor or its control circuits, and that the unit stops operating to prevent damage. CH29 (compressor over current) and CH21 (DC peak or IPM fault) are related but separate codes.
Likely causes
- Overload operation, which LG lists first: clogged or kinked refrigerant piping, a covered or blocked indoor or outdoor unit, a defective electronic expansion valve (EEV), or a refrigerant overcharge.
- A temporary power problem, which LG says can trigger the code by itself.
- Compressor damage, such as damaged winding insulation or a damaged motor inside the compressor.
- A compressor wiring fault: a loose U, V or W connector at the inverter board, a broken wire, or a bad contact at the compressor terminals.
- A damaged inverter (outdoor) circuit board, including its current sensing (CT) or power module (IPM).
Safe DIY checks
LG warns not to disassemble the air conditioner or replace internal parts yourself, since doing so may cause fire, electric shock, serious injury or death. The outdoor inverter board stores a high-voltage charge after power is removed, and compressor and refrigerant work requires an EPA-certified technician, so leave everything beyond a power reset and clearing the unit's surroundings to a professional.
- Turn the unit off at the remote, then switch off the breaker or outdoor disconnect.
- Wait about five minutes, restore power and try the unit again, as LG's reset steps say. If it then runs normally, LG says it was likely a temporary power issue.
- While the power is off, make sure nothing is covering or crowding the outdoor unit (covers, tarps, plants, snow) and that the indoor unit's air intake isn't blocked, since LG lists covering as a cause.
- If CH26 comes back after a reset, stop using the air conditioner and contact a licensed HVAC technician or LG Support. Repeated start attempts on a failing compressor can cause more damage.
- If the unit was installed recently, call the installer first, since piping, valve and charge problems are installation items.
🛠 When to call a pro
- Checking the installation first, following LG's flowchart: pipe clogging or distortion, covering of the indoor and outdoor units, the EEV connector and its operation, and refrigerant pressure.
- Checking the power wiring at L1 (L) and L2 (N) and rewiring if anything is wrong.
- Measuring the resistance between each pair of compressor terminals (U-V, V-W, W-U) and the insulation resistance between the terminals and the pipe, and replacing the compressor if either is abnormal. The correct winding values are model-specific (LG's manual gives a table for each compressor), so use the service manual for your unit.
- Checking the U, V, W connector at the inverter board, the compressor wires for breaks, and the compressor terminal connections for bad contact, and reassembling if needed.
- Checking the inverter board's IPM (power module) and replacing the inverter PCB if it is faulty. If everything tests normal, LG says to recheck the power and installation conditions.
Parts that commonly fix it
Always match the part number to your exact model.
Outdoor unit inverter board
Only if a technician finds the IPM or board faulty after the compressor and wiring test good; match the exact LG model and part number.
Search eBay →Digital multimeter
Used by a technician to check compressor winding resistance and wiring with the power off.
Search eBay →Refrigerant leak detector
Helpful if the technician suspects a refrigerant charge problem while checking pressures.
Search eBay →Sources
- LG Air Conditioner Service Manual (R410A), error 26 Inverter compressor starting failure, main reasons and flowchart (p. 117-118), outdoor unit error table (p. 100)
- LG USA Support: How to Troubleshoot Error Codes CH21, CH23, CH26, CH29 and E9 on Your LG Air Conditioner
- LG Canada Support: Single / Multi-Split Air Conditioner Error Codes (code 26)
Last reviewed 2026-10-24. Always confirm against the manual for your exact model number.