CH01

Indoor Air (Room) Temperature Sensor Error

Home Appliance Error Codes LG Split AC

Can you still use it? With care until repaired

Who can fix it? Needs a technician

Typical repair time 30 minutes – 2.5 hours

Cost level High In the Saudi market: SAR 80–1,200 (≈ USD 21–320)

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 indoor board is reading an impossible value from the room air temperature sensor (thermistor), usually because the sensor or its connection is open or shorted. The unit normally stops cooling until the fault is fixed; 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

CH01 shows on the indoor unit display, or the matching LED blink pattern appears.
The unit stops cooling shortly after start-up or does not start at all.
The code comes back after switching the unit off and on again.
The fault may appear right after the indoor unit was cleaned or opened for service.

Possible causes5

Loose, corroded or poorly seated sensor connector on the indoor board.
Failed room temperature sensor with an internal open or short.
Damaged sensor wire, pinched during installation or cleaning, or chewed by pests.
Moisture or corrosion on the connector from condensate water.
Faulty sensor input circuit on the indoor PCB.

How to diagnose5

Switch the unit off at the breaker for a few minutes, then restart; if the code returns, the fault is real and not a one-off glitch.
With the power off, open the front panel and check that the sensor (usually near the air intake) is clipped in place and its wire is intact.
A technician unplugs the sensor and measures its resistance at room temperature, comparing it with the LG resistance-temperature table.
Inspect the connector pins and the board socket for corrosion or looseness.
If the sensor and wiring test good, the fault is in the indoor PCB.

How to fix5

Clean and firmly reseat the sensor connector.
Repair the sensor wire if it is cut or its insulation is damaged.
Replace the room temperature sensor with the correct part for the model.
Replace the indoor PCB if the sensor and wiring are proven good.
Run the unit and confirm it cools normally without the code returning.

Repair cost

Cost levelHigh

Low

Medium

High

Very high

In the Saudi market: SAR 80–1,200 (≈ USD 21–320)

Our prices come from the Saudi market, converted at a fixed rate (SAR 3.75 per USD). Prices in your country may differ a lot, so we show the cost level.

Most cases are solved with a new sensor or a connector repair at low cost; the price rises only when the indoor PCB has to be replaced.

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

Can I keep using the AC with CH01?

Usually not, because the unit stops or cannot control the room temperature. A reset may clear a one-off glitch, but a returning code means the sensor or its connection needs checking.

Why did CH01 appear after cleaning the AC?

The sensor may have slipped out of its clip, the connector may be wet, or the wire may have been pinched. Let the unit dry, then check the sensor and its connector are seated.

Is the room sensor an expensive part?

No. It is one of the cheapest AC parts and quick for a technician to fit; the cost is higher only if the indoor PCB is at fault.

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