Has your LG air conditioner suddenly stopped cooling and started flashing a cryptic code like CH05, CH38, or CH04 on its display panel? Seeing these flashing lights can be alarming, but there is no need to panic—these LG AC error codes are part of a built-in self-diagnostic system designed to protect your appliance from severe damage. While some codes point to communication glitches or minor airflow obstructions that you can quickly resolve with a simple 5-minute power reset, others flag technical issues like low refrigerant or hardware failures that require a professional touch. This comprehensive troubleshooting guide will help you decode exactly what your LG air conditioner is trying to tell you, separate simple DIY fixes from professional repairs, and get your climate control back up and running smoothly. If the LED lamp blinks or an error code [CH 00] appears on the display, your unit requires inspection. The error may be a temporary one caused by power instability or other electrical factors.
Follow these steps.
Turn off the AC, unplug it or flip its circuit breaker, and wait exactly 5 minutes to clear temporary electronic glitches before turning it back on.
• Slide out the indoor mesh filters and wash away any dust buildup, as restricted airflow frequently triggers safety error codes like CH61 or CH34.
If you are using a portable or window AC, remove the rear drain plug to empty the internal water collection tray, which instantly resolves CH04 or FL errors.
➔ Unplug the power cord or turn off the circuit breaker, wait for 5 minutes, then restore power.
If the same error code or symptoms persist, a thorough inspection by a technician is necessary.
- Below is a detailed troubleshooting guide for each error code.
The letters CH precede the error codes listed below.
Select the error code being displayed on your AC.
* If you encounter any error codes not listed below, it is recommended to request a service technician for a detailed inspection, as self-resolution may be difficult.
CH 04 indicates a drainage issue, possibly a malfunction of the indoor unit drain, or that the condensate tank is too full.
[Ceiling type air conditioner]
The error code CH04 indicates that water (condensate) formed inside the indoor unit is not being
drained.
Unplug the power cord or turn off the circuit breaker, wait for 5 minutes, then restore power.
If the same issue persists after performing a reset, please request service.
[Window type, Portable type]
These types of air conditioners are designed so that condensate (water) formed during operation naturally
evaporates.
However, on rainy days or when humidity is high, condensate amount may increase, causing an
CH04/FL error.
For these types of air conditioners, condensate to resolve the error. Cooling mode will still operate as
normal, so please rest assured.
However, if the CH04/FL error occurs frequently, even on dry days, product inspection is necessary.
※ Depending on your product model and software update, the error code CH04 may appear as FL.
1. Power off the appliance and unplug the power cord.
2. Prepare a bowl or pan, about 1.5L in volume, to hold condensate.
3. The drain port is located on the lower rear of the appliance. There can be either one or
two ports.
Remove the drain cap. Allow the condensate to drain into the prepared pan.
4. After finishing draining, securely screw the cap back on.
Error codes CH05 / E0 / CH53 may occur if a communication error occurs between the indoor and outdoor units.
This error code indicates a communication issue between the indoor and outdoor units of inverter air
conditioners.
If the error persists after performing a power cycle, please request service.
The error may have been caused by an unstable power supply or other electrical issues.
To resolve the error, unplug the power cord or turn off the circuit breaker, wait for 5 minutes, then
restore
power.
If the issue continues after the power cycle, please request service.
Error code CH07 may appear on a 2-in-1 heating and cooling air conditioner when the standing and wall-mount
units are set to different operating modes.
This error can also occur with ceiling-type air conditioners when units in different rooms are running in
conflicting modes.
For example, if the AC in the living room is set to cooling while the AC in the bedroom is set to heating,
error code CH07 may be displayed
Check the operating mode of each air-conditioning unit.
Please set them all to either heating or cooling/dehumidification.
Cooling and dehumidification modes cannot be used at the same time as heating mode.
Example: For a 2-in-1 air conditioner
| Standing | Wall mount | Operation (Y/N) |
|---|---|---|
| Cooling | Cooling | Operation possible |
| Cooling | Dehumidification | Operation possible |
| Dehumidification | Cooling | Operation possible |
| Dehumidification | Dehumidification | Operation possible |
| Heating | Heating | Operation possible |
| Heating | Cooling | CH07 error |
| Heating | Dehumidification | CH07 error |
| Cooling | Heating | CH07 error |
| Dehumidification | Heating | CH07 error |
Move left or right to check the contents.
※ Air Purification and Fan modes can be used at any time without restrictions.
CH38 / F4 errors indicate that the air conditioner is low on refrigerant (gas).
This warning is designed to protect the appliance from potential damage.
If so, the error likely points to a refrigerant shortage.
Please contact the installation technician to inspect the unit.
You can find their contact information on the business card provided during their visit or on the side of
the
unit.
The piping connection may also need to be checked.
For accurate diagnosis, please consult the installation technician.
The issue may be temporary, caused by unstable power or other electrical factors.
Unplug the power cord or turn off the circuit breaker, wait for 5 minutes, then restore power.
If the error reappears after performing a power cycle, please contact LG support for assistance.
The CH54 error may occur after a temporary power outage or electrical work.
If the error persists, the unit will require inspection.
If the error appeared after electrical work, please contact the contractor and inform them of the reverse
phase detection error, so they can take corrective action.
The CH61 error may occur when the outdoor unit overheats during cooling, or when the indoor unit overheats during heating.
[Cooling Mode]
If the temperature of the outdoor unit becomes too high during cooling operation, the CH61 error may
appear.
This often happens when the area around the outdoor unit is not well-ventilated, causing hot air to
accumulate
and raise the temperature.
The error is designed to prevent overheating and potential damage or fire.
[Heating Mode]
During heating operation, CH61 may occur if the indoor unit’s internal temperature becomes too high.
This is typically caused by poor air intake, often due to a clogged or dirty air filter.
Depending on the product model, the error may appear as P4, P6, P7, P8, or CH34.
➔ Please open the ventilation window or insect screen.
If the temperature in the balcony becomes too high, hot air may flow back into the air conditioner.
➔ Clear any obstacles around the unit to ensure proper ventilation.
If items are piled up near the outdoor unit, hot air cannot escape effectively.
➔ Adjust the unit so it aligns with the ventilation window.
If it is installed too low, consider using a stand to raise its height.
➔ Install an air guide.
An air guide helps direct the hot air from the outdoor unit to the outside environment.
According to LG's testing, installing an air guide can lower the outdoor unit room temperature by about
6–8°C.
➔ Please clean the indoor unit filter.
The CH61 error will not automatically clear. To clear the error, perform a power
cycle.
To reset the unit: Unplug the power cord or turn off the circuit breaker, wait for 5 minutes, then restore
power.
※ If the same issue persists, inspection by a service technician is required.
The CH66 error occurs when there is an issue with the communication line or piping connection between the indoor and outdoor units.
The CH66 code is a feature in inverter models that detects communication or piping connection issues
between
the indoor and outdoor units.
If the error appeared immediately after installation, please contact the installation technician.
In this case, the error may have been caused by a temporary fault due to unstable power supply or other
electrical factors.
Unplug the power cord or switch off the circuit breaker, wait about 5 minutes, then restore power.
※ If the issue persists, the unit may require inspection by a service technician.
CH10 / E6 errors are caused by issues with the indoor unit fan, while CH67 / EF errors are related to the outdoor unit fan.
Check for any debris or snow buildup around the indoor and outdoor fan components, and remove it.
If there are no visible issues, service may be required.
※ If the issue persists, please contact a service technician for inspection.
CH90 / CH91 errors are typically displayed during the test run phase to prevent damage to
the appliance.
On some models, the error may be displayed as F4.
In this case, the piping connections should be checked.
Please consult the installation technician.
You can find their contact information on the business card provided during their visit or on the side of
the
unit.
➔ Unplug the power cord or turn off the circuit breaker, wait about 5 minutes, then restore power.
This error may have occurred temporarily due to unstable power supply or other electrical factors.
If the issue persists, please request service.
The CH93 error code indicates a communication problem between the indoor and outdoor units.
The CH93 error typically occurs during the test run when communication between the indoor and outdoor units
is
not stable.
For models released after 2021, this error can also appear if the outdoor unit is not receiving power.
Please inspect the power cord and cable connections.
If the issue persists, please request service.
This error may temporarily occur due to unstable power supply or other electrical factors.
Unplug the power cord or turn off the circuit breaker, wait about 5 minutes, then restore power.
If the issue persists, please request service.
For some air conditioner models manufactured after 2021, the communication line
configuration has changed,
and each unit now comes with a separate power cord.
These models require both the indoor and outdoor units to be connected to power for proper operation.
Error codes begin with "CH" followed by numbers.
➔ Securely plug the power plug directly into a wall outlet.
Avoid using a power strip with the air conditioner, as sharing power with other appliances may exceed the
power strip’s capacity.
Always connect the air conditioner’s power plug to a wall outlet.
➔ Check the air conditioner and switch the AC’s breaker back on.
If the breaker does not turn on, do not attempt to reset it repeatedly.
In this case, please request service.
This guide was created for all models, so the images or content may be different from your product.
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