Run a quick self-check to resolve simple issues while saving time and
money.
Checking your unit before the summer heat arrives can also help prevent
major breakdowns.
1. Check the Power Supply and Remote Control
Checking the Power Supply
-
- Check the outlet connection.
➔ If you unplugged the unit after last summer, plug it back in before running a self-check.
-
- If you’re using a power strip, check this first.
➔ Do not use a power strip or extension cord. Plug the power cord directly into a wall outlet.
➔ If using a power strip is unavoidable, use a power strip rated for air conditioners.
※ Note: Ensure the power strip's maximum capacity meets the product specifications listed in the owner's manual.
-
- Check that the plug fits snugly in the wall outlet.
➔ If the outlet is loose or does not hold the plug firmly, have the outlet replaced by a qualified electrician.
-
- Check the wall outlet for burn marks.
➔ Check for burn marks on the outlet slots or on the power plug. If you see any scorch marks, have the outlet or power plug replaced by a qualified electrician.
-
- Check the dedicated air conditioner circuit breaker.
➔ If your model uses a dedicated circuit breaker, switch it to ON.
※ Note: 2021 and newer models require separate power connections for the outdoor unit, floor-standing indoor unit, and wall-mounted indoor unit.
Refer to the user manual for more details.
Checking the Remote Control Batteries and Operation
- Does the remote control display remain off when you press a button?
➔ Replace the batteries with new ones.
The batteries may be drained. Open the back cover and replace the
batteries with new ones.
Then, press the [Start/Stop] button on the remote control to check if
the display turns on.
If the display remains blank or characters appear and then disappear
even after replacing the batteries, the remote control may have a
problem.
If you won’t use the remote control for an extended period, remove
the batteries and store them separately.
This helps prevent battery discharge and leakage, which can damage the
remote control.
- Does the display turn on, but the remote control still doesn’t work?
➔ Use your smartphone camera to check if the remote is sending a signal.
Check the Remote Control Transmitter
- 1. On an Android phone, open the Camera app and point the camera lens at the top of the remote control.
-
2. Look at your phone screen and press the [Start/Stop] button on the
remote repeatedly.
If you see a red light blinking on your phone screen, the transmitter is working normally. -
3. If you see the light but the unit still doesn’t respond, the
receiver on the floor-standing or wall-mounted unit may need to be
checked.
If the issue persists, contact LG customer support for service.
Caution: Some smartphones, such as iPhones, may not detect the infrared
signal.
Use an Android phone camera instead.
- Are some buttons on the remote control not working?
➔ Check the location of the receiver on the unit.
Point the remote toward the signal receiver on the unit.
Ensure you are within the operating distance (7 m) and angle (45°
left/right).
You should hear a beep sound when the unit receives a command.
The sound indicates that the indoor unit has successfully received the
command.
The remote control is designed for multiple models.
Depending on your model, some functions may not be available. If you
hear a buzzer sound or rapid beeping sound, it indicates that the
function is not supported.
2. Check the filter condition and where the outdoor unit is installed.
Filter Cleaning and Replacement
* Removal steps may vary by model.
- Floor-standing Air Conditioner
- Unplug the power cord for safety before cleaning.
- Pull the filter handle on the back of the unit sideways to remove the filter.
- For models with an air purification function, unhook the top and bottom tabs of the ultra-fine filter to separate it from the internal filter.
➔ Unplug the power cord before cleaning inside the unit.
➔ After removing the ultra-fine filter, remove dust using a vacuum
cleaner or wash with a soft brush under running water.
If the filter is heavily soiled, wash it with a diluted neutral
detergent and rinse thoroughly. (Do not use water hotter than 40°C.)
➔ Dry the filter completely in a well-ventilated, shaded area.
- Wall-Mounted Air Conditioner
Check the filter type for your model. (Refer to the image below.)
* Filter removal steps vary by model.
➔ Remove the ultra-fine filter.
➔ After removing the filter, remove dust using a soft brush or a vacuum
cleaner.
If heavily soiled, wash with a neutral detergent and rinse thoroughly
with clean water. (Do not use water hotter than 40°C.)
➔ Dry the filter completely in a well-ventilated, shaded area.
For models equipped with Deodorizing filters or TVF (allergy, virus) filters, do not wash these filters with water. Replace these filters regularly.
- How do I clean the filter on a Casement Window Air Conditioner?
- 1. Turn off the unit and unplug the power cord.
- 2. At the top front of the unit, press the upper part of the ultra-fine filter cover until it clicks, then pull it toward you.
- 3. Hold the handle on the ultra-fine filter and pull it out to the side to remove it.
- 4. Clean the filter with lukewarm water (below 104°F / 40°C) or replace it with a new one if necessary.
- How do I clean the filter on a Window Air Conditioner?
- 1. Turn off the unit and unplug the power cord.
- 2. Pull the front cover forward to remove it.
- 3. Pull the ultra-fine filter forward and then lift it upward.
- 4. Clean the filter or replace it with a new one if necessary.
- How do I clean the filter on a Portable Air Conditioner?
Single Hose Model
- 1. Turn off the unit and unplug the power cord.
- 2. Detach the rear ultra-fine filter cover and remove the filter.
- 3. Clean the filter or replace it with a new one if necessary.
Dual Hose Model
- 1. Turn off the unit and unplug the power cord.
- 2. Remove the screw below the dual hose and detach the hose.
- 3. Detach the rear ultra-fine filter cover and remove the filter.
- 4. Clean the filter or replace it with a new one if necessary.
Checking the Outdoor Unit Surroundings
- Check the area where the outdoor unit is installed.
➔ Remove any items stacked in front of, behind, or around the outdoor unit.
If airflow is blocked, cooling may be weak or may not work at all.
- If the outdoor unit is in an enclosed space, open the ventilation window so hot air can vent outside.
➔ Adjust the louvers to be as horizontal as possible to maximize airflow. If there is an insect screen, open it alongside the window.
If the screen is clogged with dust, it will block air circulation. Use a cleaning brush to remove dust and ensure clear airflow.
If hot air still can’t vent out, install an air guide to help direct the heat outside.
- Is the outdoor unit installed in a very hot location?
During a heatwave, high outdoor temperatures can raise the temperature
inside the outdoor unit.
The air conditioner may not cool properly when the outdoor temperature
is below 18°C (64°F) or above 48°C (118°F).
In hot summer weather, if the outdoor unit is exposed to direct sunlight
and overheats, it may fail to produce cool air even after running for a
long time.
If your outdoor unit is installed in a location with heavy sun exposure,
installing a sunshade can significantly improve cooling performance.
Secure the sunshade firmly so it won’t be blown away by the wind. Do not cover the back or sides of the unit.
- Is there a lot of dirt, debris, or dust on the outdoor unit?
If the heat exchanger on the back of the outdoor unit is clogged with
dust, air can’t pass through. This can prevent the outdoor unit from
cooling down, which may weaken cooling performance or trigger an
error.
If the heat exchanger is dusty, clean it. Wearing protective gloves, use
a thick-bristled toothbrush or cleaning brush to remove dust by sweeping
vertically from top to bottom.
Be careful not to bend the heat exchanger fins or injure your hands
while cleaning.
※ Note: You can also clean the unit with water. However, spray the water downwards so that it washes the dust away like rain.
Checking the Indoor Unit Area
- Organize the area around the indoor unit's air intake (where the filter is installed).
➔ Ensure curtains or objects do not block the air intake (filter area). Blockage can cause noise and weak performance.
3. Check cooling with a test run, and check the drain hose
How to Perform a Test Run
➔ LED Type Floor-standing Models
- 1. 1. Press and hold the [Power] and [Temperature Down] buttons simultaneously for 3 seconds.
- 2. When you hear a beeping sound once, release the buttons. The test run will begin.
-
3. During the test run, [Lo] will appear on the display for about 3
minutes. Then, the required test progress will be displayed from [1 to
99] for approximately 4 minutes.
Immediately after, [EN] appears and the selected operation runs automatically for about 10 minutes.
The total test run takes about 17–20 minutes. Wait until it finishes.
➔ LED Type Wall-mounted Models
- 1. Hold the air outlet or the sides of the front panel, and lift the front cover upward to open it.
-
2. Press and hold the [Forced Operation] switch on the right side of
the unit for 3–6 seconds.
When you hear a single beep, release the switch. The test run will start. -
3. Models with LED Display: During the test run, [Lo] will appear on
the display for about 3 minutes.
Then, the required test progress will be displayed from [1 to 99] for approximately 4 minutes. Next, [EN] appears and the selected operation runs automatically for about 10 minutes. -
4. Models with LED Lamps (3 LED): During the test run, the [Power] →
[Outdoor Unit] → [Timer] lamps turn on in order and the required test
operation runs for about 7 minutes.
Next, the [Power] and [Outdoor Unit] lamps turn on at the same time, and a selected operation runs automatically for about 10 minutes.
[LED Models]
[3 LED Models]
➔ LCD Type Floor-standing Models
- 1. Press and hold the [Power] and [Temperature Down] buttons simultaneously for 3 seconds.
- 2. When you hear a single beep, release the buttons. The test run will start.
-
3. During the test run, the unit displays the progress for about 7
minutes.
Immediately after, the selected operation runs automatically for about 10 minutes.
The total test run takes about 17–20 minutes. Wait until it finishes.
➔ Test Run Using the Remote Control
-
1. Turn on the power.
When power is supplied normally, you will hear a chime. - 2. Press the [Set/Cancel] button on the remote control for the wall-mounted unit 3 times within 5 seconds.
During the test run, do not press the [Forced Operation] switch or any
other buttons on the remote control.
If you press any button, the test run may stop before it finishes, and
the unit may not operate normally.
Checking the drain hose
- Check the Drain Hose
If the hose is disconnected or torn, reconnect it securely and wrap the
connection point with electrical tape.
If you are unable to perform this repair yourself, contact LG Support
for service.
- Make sure the end of the drain hose is not submerged in water when connected to a container.
If the end of the hose is submerged, water may flow back into the unit
and cause leakage.
To prevent this, empty the water container regularly so that the hose
does not become submerged.
- Ensure the drain hose is straight and free of bends.
➔ If the hose has severe bends and you cannot fix it yourself, it should be checked by a professional service technician.
- Make sure the drain hose slopes downward
If the hose is not angled downward or has bends, water may not drain
properly and can flow back into the unit.
Adjust the hose so it is straight and sloping downward for smooth
drainage.
This guide was created for all models, so the images or content may be different from your product.


