LG Inverter AC Error Code CH38: Causes, Fixes & Troubleshooting Guide
Learn what the LG Inverter AC CH38 error code means, its common causes, how to troubleshoot the issue, reset your air conditioner, and when to call a technician.
ERROR CODES
6/28/20264 min read
If your LG Inverter air conditioner is displaying the CH38 error code, it typically indicates a low refrigerant condition or that the system has detected insufficient refrigerant pressure. This safety feature helps protect the compressor from damage caused by operating with too little refrigerant.
The CH38 error is one of the more common fault codes on LG inverter air conditioners. While a temporary power issue may occasionally trigger the code, it is often caused by a refrigerant leak or a problem within the cooling system.
This guide explains what the LG Inverter AC CH38 error means, its possible causes, troubleshooting steps, and when professional repair is necessary.
What Does LG Inverter AC Error Code CH38 Mean?
The CH38 error code indicates that the air conditioner has detected low refrigerant levels or low refrigerant pressure.
Since refrigerant circulates in a sealed system, a low refrigerant condition usually means:
There is a refrigerant leak.
The system was undercharged during installation or servicing.
A refrigeration component has failed.
The pressure detected by the system is outside the normal operating range.
To prevent compressor damage, the air conditioner may stop cooling or shut down automatically.
Common Causes of LG AC Error Code CH38
1. Refrigerant Leak
The most common cause of the CH38 error is a refrigerant leak.
Leaks may develop in:
Refrigerant pipes
Flare connections
Indoor evaporator coil
Outdoor condenser coil
Service valves
Even a small leak can eventually reduce refrigerant enough to trigger the error.
2. Low Refrigerant Charge
If the air conditioner was recently installed or repaired, the refrigerant charge may be insufficient.
Improper charging can reduce cooling performance and activate the CH38 fault.
3. Damaged Refrigerant Pipes
Bent, cracked, or corroded refrigerant lines may restrict refrigerant flow or allow refrigerant to escape.
4. Faulty Pressure Sensor
The pressure sensor monitors refrigerant pressure throughout the system.
If the sensor provides inaccurate readings, the control board may display the CH38 error even when refrigerant levels are normal.
5. Faulty Control Board
Although less common, a malfunctioning indoor or outdoor control board can incorrectly trigger refrigerant-related error codes.
Symptoms That May Accompany the CH38 Error
When the CH38 error appears, you may notice:
Air conditioner stops cooling
Indoor unit turns off unexpectedly
Warm air blowing from the vents
Compressor fails to start
Reduced cooling performance
Error code remains after restarting
Outdoor unit not operating normally
How to Fix LG Inverter AC Error Code CH38
Step 1: Turn Off the Air Conditioner
Switch off the unit using the remote control.
Then disconnect power at the circuit breaker for several minutes before restarting.
A temporary electronic fault may clear after a power reset.
Step 2: Check for Obvious Refrigerant Line Damage
Inspect the copper refrigerant pipes connecting the indoor and outdoor units.
Look for:
Oil stains around fittings
Physical damage
Loose flare connections
Signs of corrosion
Oil residue often indicates a refrigerant leak.
Step 3: Clean the Air Filters
Although dirty filters usually do not directly cause CH38, restricted airflow can reduce cooling efficiency.
To clean the filters:
Turn off the AC.
Remove the front cover.
Remove the air filters.
Wash with clean water.
Allow them to dry completely.
Reinstall the filters.
Clean filters improve airflow and overall performance.
Step 4: Inspect the Outdoor Unit
Make sure the outdoor condenser unit:
Has proper airflow
Is free of leaves and debris
Has clean condenser fins
Is not blocked by nearby objects
Poor airflow can increase operating stress on the system.
Step 5: Do Not Attempt to Add Refrigerant Yourself
Unlike window air conditioners, inverter split systems require specialized tools to:
Detect refrigerant leaks
Measure operating pressures
Evacuate the system
Recharge with the correct refrigerant amount
Adding refrigerant without repairing the leak will only provide a temporary solution.
Step 6: Have the Refrigerant System Inspected
If the CH38 error returns after restarting the unit, a qualified HVAC technician should:
Perform a leak test
Repair any refrigerant leaks
Recharge the system to manufacturer specifications
Verify proper operating pressure
Test the pressure sensor if necessary
How to Reset LG Inverter AC CH38 Error
You can perform a simple reset by following these steps:
Turn off the air conditioner.
Switch off the circuit breaker or unplug the unit if applicable.
Wait 5 to 10 minutes.
Restore power.
Restart the air conditioner.
If the CH38 code immediately returns, the system likely has an actual refrigerant or sensor issue that requires repair.
Can You Continue Using the AC With a CH38 Error?
No.
The CH38 error is designed to protect the compressor from operating with insufficient refrigerant.
Running the air conditioner while refrigerant is low can lead to:
Compressor overheating
Poor cooling performance
Increased energy consumption
Costly compressor failure
It's best to stop using the unit until the issue is diagnosed.
How to Prevent CH38 Errors
You can reduce the risk of refrigerant-related problems by:
Scheduling annual AC maintenance.
Cleaning the air filters every two to four weeks.
Keeping the outdoor unit free from debris.
Inspecting refrigerant lines for visible damage.
Addressing unusual cooling performance promptly.
Having refrigerant levels checked only by certified technicians.
Routine maintenance helps detect small leaks before they become major problems.
When Should You Call a Technician?
Professional service is recommended if:
The CH38 error returns after resetting.
The AC no longer cools the room.
You notice oil stains on refrigerant pipes.
The compressor repeatedly shuts down.
The outdoor unit fails to operate.
Cooling performance continues to decline.
You suspect a refrigerant leak.
A certified technician has the equipment needed to locate leaks, repair the system, and safely recharge the refrigerant.
Frequently Asked Questions
Does CH38 always mean the refrigerant is low?
Most of the time, yes. However, a faulty pressure sensor or electronic control board can also trigger the error.
Can I simply refill the refrigerant?
No. Refrigerant does not get "used up" during normal operation. If the level is low, there is usually a leak that should be repaired before recharging the system.
Will resetting the AC remove the CH38 error?
A reset may clear a temporary electronic glitch, but the error will return if the underlying refrigerant or pressure problem still exists.
Is it safe to continue using the air conditioner?
No. Continuing to operate the system with a genuine CH38 fault may damage the compressor and lead to more expensive repairs.
Final Thoughts
The LG Inverter AC CH38 error code usually indicates that the air conditioner has detected low refrigerant pressure or insufficient refrigerant, often due to a leak within the sealed cooling system. While simple steps such as resetting the unit, cleaning the filters, and checking for obvious pipe damage are worthwhile, refrigerant-related issues generally require professional diagnosis and repair.
If the CH38 error persists after basic troubleshooting, stop using the air conditioner and arrange for qualified service. Repairing refrigerant leaks early can restore cooling performance, protect the compressor, and help avoid more costly repairs in the future.