Indoor unit displays CH02 and refuses to start or stops intermittently.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety warning: Disconnect power at the breaker before opening the indoor unit. Avoid touching live terminals.
Diagnostic and repair steps:
- Reset power: Turn the breaker OFF for 5 minutes, then ON. If CH02 reappears, proceed.
- Open indoor unit: Remove the front panel and filters, then remove the screws to access the coil and control board area.
- Locate the pipe thermistor: It is usually clipped directly to the evaporator coil tubing (small sensor head with two wires).
- Check mounting: Ensure the sensor is firmly clipped to the copper tube. If it has fallen off, reattach it securely; a loose sensor can trigger CH02.
- Inspect wiring: Follow the sensor wires back to the PCB. Look for cuts, pinches, or burn marks. Reseat the connector on the PCB.
- Measure resistance: With a multimeter, check resistance across the thermistor. Compare to LG service data if available; an open or short indicates failure.
- Replace sensor if needed: Install a new LG indoor pipe thermistor if the old one is defective. Route and secure wiring away from sharp metal edges and moving parts.
- Reassemble and test: Refit covers, restore power, and run the unit. Confirm CH02 is cleared and cooling is normal.
Call a professional if: The sensor and wiring are good but CH02 persists, as the indoor PCB or firmware may be faulty.
Repair Difficulty
Required Part
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