CH26

Inverter Compressor Start Failure (Position Detection)

Home Appliance Error Codes LG Split AC

Can you still use it? No, unplug it

Who can fix it? Needs an authorized technician

Typical repair time 1 hour – 8 hours

Typical cost SAR 150 to 5,000

What it means

This code appears on LG inverter split air conditioners and on LG ducted and cassette units that use CH codes. It means the outdoor inverter board could not detect the compressor rotor position during start-up, so the compressor did not begin to turn. The unit tries to start several times, then stops and shows the code. The same code can mean something else on other brands.

Models covered: LG inverter split air conditioners (e.g. Dual Inverter) and LG ducted/cassette units that use CH codes; the code shows as CH plus a number on the display or as LED blinks.

Symptoms4

CH26 shows and the compressor does not run at all.
A brief hum or vibration comes from the outdoor unit without the compressor turning.
The outdoor or indoor fan runs but there is no cooling.
The code may appear when the unit is restarted straight after being switched off.

Possible causes5

Loose compressor connector, a broken wire among the three, or wires in the wrong order after service.
Failed IPM or outdoor inverter PCB.
Mechanically seized compressor or damaged windings.
Unequalized system pressure on a quick restart, or a large refrigerant overcharge.
Low supply voltage at the moment of start-up.

How to diagnose5

Switch off the breaker and wait several minutes for pressures to equalize, then restart.
After discharge, a technician checks the compressor connector, the three wires and their order against the LG diagram.
Measure winding resistance across the three compressor terminals, confirm they are balanced, and check insulation to the compressor body.
Test the IPM per the service manual, using an inverter checker if available.
Measure supply voltage during start-up and check the refrigerant charge.

How to fix6

Reconnect the compressor plug firmly and in the correct order.
Replace a damaged compressor wire.
Fit a voltage protector if the supply collapses during start-up.
Replace the outdoor PCB if the IPM is proven faulty.
Replace the inverter compressor if it is seized or its windings are damaged, with vacuum and the correct recharge.
Run the unit and confirm the compressor starts smoothly every time.

Repair cost

0–200

200–600

600–1,500

1,500+

In Saudi riyals; the highlighted part is the expected range for this fault.

The cost is low for a connector or wire, moderate to high for an outdoor PCB, and highest for a new inverter compressor.

Prices are rough estimates including the part and the technician’s fee, and vary with brand, model and part source.
Prices last updated: September 2026

Frequently asked questions

Is a single CH26 serious?

If it appeared after a quick off-on restart and cleared after waiting, unequal pressure may be the reason. If it repeats, there is a wiring, board or compressor fault.

How does the technician know the compressor is to blame?

By measuring the windings and insulation and testing the IPM. Balanced, healthy windings point to the outdoor PCB; otherwise the compressor is at fault.

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This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

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