CH02

Indoor Pipe (Inlet) 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

Typical cost SAR 80 to 1,200

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 thermistor on the evaporator inlet pipe is giving an impossible reading because of an open or short circuit. The unit relies on this sensor to protect the coil from freezing and to control the compressor, so it normally stops when the code shows. 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.

Symptoms3

CH02 shows on the display or as the matching blink pattern.
The outdoor compressor stops while the indoor fan keeps running, or the whole unit stops.
The code returns right after restarting or within a few minutes.

Possible causes5

Sensor slipped out of its holder on the pipe, loose clip, or unplugged connector.
Failed sensor, often from constant moisture on the cold pipe.
Damaged or corroded wire near the pipe or where it passes the coil fins.
Corrosion or water on the sensor connector at the indoor board.
Faulty sensor input circuit on the indoor PCB.

How to diagnose5

Switch off the breaker for a few minutes, restart and watch whether the code returns.
A technician checks that the sensor sits inside its holder on the evaporator inlet pipe and the wire is not cut.
Unplug the sensor, measure its resistance and compare it with the LG resistance-temperature table; warming it by hand should change the reading.
Inspect the connector and board socket for corrosion or moisture.
If the sensor reads correctly, check the sensor input on the indoor PCB.

How to fix5

Refit the sensor in its holder on the pipe and clean the connector.
Repair the damaged wire and seal it well against moisture.
Replace the evaporator pipe sensor with the correct part.
Replace the indoor PCB if the sensor is good.
Run the unit in cooling and confirm the compressor runs and the code does not return.

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 usual fix is a new sensor or refitting it at low cost; the top of the range covers a faulty indoor PCB.

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

What is the difference between CH01 and CH02?

CH01 is the room air sensor. CH02 is the sensor on the evaporator pipe that watches coil temperature and protects it from freezing.

Does CH02 mean low refrigerant?

No. It points to an electrical fault in the sensor or its wiring, not to the refrigerant charge. LG uses a different code, CH38, for refrigerant shortage.

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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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