LG Portable Air Conditioner Not Cooling

Portable air conditioners are incredibly convenient, and LG portable AC units excel in delivering this convenience. However, a common issue that many users encounter is an LG portable air conditioner not cooling. This problem can leave you scratching your head.

Frequently, an LG portable air conditioner doesn’t cool properly. This can happen if it’s too small for the space, doesn’t have enough power, or if it gets too hot. Also, things like error codes, a remote that doesn’t work, wrong temperature settings, a slow fan, or air leaks can be the reasons.

Several factors could be causing this cooling hiccup. It may be due to a dirty filter or condenser coils, limited clearance, obstructed vents, low refrigerant levels, frozen evaporator coils, or a particularly humid environment. Additionally, critical components such as the fan, compressor, thermistor, thermostat, and temperature control board might be malfunctioning, or the AC unit itself could be unresponsive.

In total, there are about 19 potential issues that can slow down your cooling experience, and this LG Portable AC troubleshooting guide is here to assist you in identifying and resolving them.

Let’s get started!

LG Portable Air Conditioner Not Cooling

Quick DIY Troubleshooting Guide for an LG Portable Air Conditioner Not Cooling

Likely CauseRecommended Fix
1. AC Capacity MismatchEnsure the AC’s BTU matches the room size recommendations.
2. Power InterruptionVerify that the AC is turned on, reset the breaker if necessary, and replace blown fuses.
3. Excessive Heat ExposureRelocate the AC away from direct sunlight and heat sources like ovens or heaters.
4. Error CodesAddress any displayed error codes according to the user manual.
5. Non-Responsive RemoteCheck the remote’s functionality, repair, or replace it if needed.
6. Incorrect Temperature SettingsAdjust the thermostat settings to a cooler temperature or switch to Cool Mode.
7. Low Fan SpeedIncrease the fan speed setting to high for better airflow.
8. Air LeaksSeal any air leaks around windows, doors, walls, and AC vents; replace damaged vents.
9. Dirty Air FilterClean the air filter if it’s clogged or dirty.
10. Dirty Condenser CoilsClean the condenser coils if they are covered in dirt or debris.
11. Limited ClearanceEnsure at least a 20-inch clearance around the AC for optimal airflow.
12. Blocked Air VentClean dirty air vents and straighten any kinks in the vent tubing.
13. Low Refrigerant LevelsArrange for professional inspection and repair of refrigerant leaks.
14. Frozen Evaporator CoilsTurn off the AC to allow the coils to defrost.
15. High HumidityUse a drain tube or set the AC to Cool or Dry Mode to tackle humidity.
16. Faulty ComponentReplace any faulty components such as the fan, capacitor, compressor, or sensors.
17. Exhaust Hose BlockageEnsure the exhaust hose is clear of obstructions for efficient heat removal.
18. Evaporator or Condenser Fan IssuesExamine and replace malfunctioning fans for proper airflow.
19. AC Unit Not FunctioningAs a last resort, consider replacing the entire air conditioner.
LG air conditioner troubleshooting manual table

Why does my LG Portable Air Conditioner Not Cooling?

In most cases, your LG portable air conditioner isn’t cooling due to one of the problems shared below:

1. AC Capacity Mismatch

Sometimes, when your portable AC doesn’t cool properly, it’s not because the AC is faulty but because it’s the wrong size. This can affect both cooling and heating performance. It’s not just about getting a smaller AC; having one that’s too big can also be a problem.

How to fix:

To make sure your AC matches LG’s recommended room size, refer to the table below:

Room SizeAC Capacity (BTU Rating)
200 sq.ft7,000 BTU
200 sq.ft8,000 BTU
300 sq.ft10,000 BTU
450 sq.ft11,000 BTU
400 sq.ft12,000 BTU
500 sq.ft13,000 BTU
600 sq.ft14,000 BTU

2. LG Portable Air Conditioner Not Cooling due to Power Interruption

Your AC may stop running and cooling if the power supply is suddenly interrupted while it’s on. This interruption can happen because of a power surge that blows a fuse or trips a breaker. To resolve this:

How to fix:

  1. Check if the breaker has tripped. If it’s off, reset it.
  2. Inspect the fuse. If it doesn’t have continuity, replace it.
  3. Make sure your AC is connected to a power source and has electricity.

3. LG Portable Air Conditioner Won’t Cool Enough due to Excessive Heat Exposure

When your AC is exposed to direct sunlight, it struggles to cool effectively. Even if it manages to cool, you won’t feel the cold air because of the intense heat. The same goes for indoor situations with a heat source like a burning stove, a running computer, or a powered heater. High temperatures interfere with the AC’s cooling.

To fix this:

Move your AC away from direct sunlight and any indoor heat sources.

Why does my LG Portable Air Conditioner Not Cooling

4. Error Codes

Sometimes, your air conditioner may stop cooling due to various errors. To get your AC back on track, it’s essential to identify and clear these errors. For instance, if you see error code E3 or CH03, it means your AC is low on refrigerant, which can hinder cooling.

Other error codes like FL, E5, and P2 can also affect your AC’s cooling.

To fix this:

Start by clearing the error code. Refer to LG’s error code troubleshooting guide or manual for this.

5. Non-Responsive Remote

If you rely on your remote control to operate your AC and it doesn’t respond, it’s vital to address this issue. Sometimes, the trouble might be with the remote itself, not the air conditioner.

How to fix:

If your remote control isn’t working with your AC, start by checking if it’s operational by pressing its buttons. If there’s no response, try replacing the batteries. Additionally, make sure you’re close to the AC when using the remote, as the signal may not reach if you’re too far away. These steps should help you get your remote working again.

6. Incorrect Temperature Settings

To ensure your portable AC blows cool air, it should be set to a lower temperature, typically in Cool Mode. If you select a higher temperature or switch to the heat mode, your LG portable air conditioner will warm the room instead of cooling it.


To resolve this issue, set your AC to Cool Mode, if it isn’t already. Always make sure that the selected temperature on the AC is lower than the current temperature in your room. This will help your AC cool the space effectively.

7. Low Fan Speed

If your air conditioner’s fan is spinning slowly, it won’t deliver cool air effectively. A faster fan speed is crucial to promote proper airflow and distribute the cooled air throughout the room. To address this issue:

How to fix:

Increase the fan’s speed setting to ensure it blows cool air at a faster rate, improving the cooling efficiency of your air conditioner.

8. Air Leaks

Your LG portable air conditioner may not blow cold air because of an air leak. If there are gaps around your doors, windows, or walls, warm air can sneak in while the cool air escapes. The same goes for a damaged vent.

To fix it:

  1. Seal any gaps around doors, windows, and walls to keep the cool air in.
  2. Check the vent hose for cracks or tears. If you find any, try to seal them. If that doesn’t work, replace the hose.

9. LG Portable AC Not Cooling due to Dirty Air Filter

A dirty air filter can make your LG air conditioner stop blowing cold air. To keep things cool, you should clean the filter every two weeks, as recommended by LG.

Here’s what happens: When the filter gets clogged with dirt, it blocks the cold air from flowing out, so your AC can’t do its job.

To fix it:

  1. Take out the air filter and give it a good cleaning. Use warm water with a mild detergent.
  2. Let it dry completely before putting it back in.

10. Dirty Condenser Coils

Dirty condenser coils can cause your AC to stop cooling. These coils help get rid of heat by circulating refrigerant.

But if they’re covered in dirt, they can’t do their job, and your room will stay hot instead of getting cool.


  1. Check the condenser coils for dirt.
  2. Clean them using an AC coil cleaner solution.

11. Limited Clearance

To make your portable AC work better and cool your room properly, it needs room to breathe. This means there should be at least 20 inches of space around it.

If there’s not enough space, your AC will have a hard time doing its job.

Here’s what to do:

Make sure there’s a clear space of 20 inches or more around your portable AC.

lg air conditioner troubleshooting manual

12. LG Portable AC is not Cooling due to Blocked Air Vent

A blocked vent can cause problems for your portable AC. It needs to have a clear path for the air to flow, and any dirt or kinks in the vent can stop that from happening.

how to fix:

  1. Check the vent hose for clogs and clean it if you find any.
  2. Straighten out any kinks in the hose to keep the airflow smooth.

13. Low Refrigerant Levels

Low refrigerant can be a big reason why your air conditioner isn’t cooling properly. Refrigerant is what helps absorb heat, so if there’s not enough of it, your room will stay warm.

Here’s what to do:

Look for signs of refrigerant leaks, like moisture around the AC and a hissing sound.

But here’s the important part:

Don’t try to fix a refrigerant leak yourself. It’s best to call in an expert to handle it.

14. Frozen Evaporator Coils

Think of your AC like a superhero with a special part called the “evaporator coil.” Its mission is to take warm air from your room and turn it into nice, cool air for you to enjoy. But, when it gets super cold around, this coil can become like an ice cube, and that’s not good.

How to fix:

Give it a break. Turn off your AC for a while, so the evaporator coil can melt away all that frost.

15. LG Portable Air Conditioner Not Cooling due to High Humidity

When it’s really humid, your LG portable air conditioner might struggle to keep things cool. That’s because the air conditioner’s water tank can fill up fast and stop it from blowing cold air.


  1. Empty the water tank regularly. You can use a drain tube to do this.
  2. Switch your AC to Dry or Cool Mode, and it should work better.

16. Faulty Component

Sometimes, if certain parts in your portable air conditioner aren’t working right, it won’t blow cold air. These parts include:

  1. Fan: If the fan is broken, it can’t spin and blow cold air. Check if it’s working.
  2. Capacitor: When the run capacitor goes bad, the compressor won’t start, and your AC won’t cool. Test it for any issues.
  3. Compressor: A faulty compressor messes up airflow, so your AC can’t cool properly. Test it to see if it’s working.
  4. Thermistor: The thermistor keeps an eye on the temperature. If it’s not doing its job, your AC might not blow cold air. Use a tool called a multimeter to check it.
  5. Thermostat: A broken thermostat can’t tell when the AC needs to cool. You can test it with a multimeter.
  6. Temperature Control Board: If this board is acting up, it won’t turn on the compressor and fan, so your AC stays warm.

How to fix it:

If you find any of these parts are faulty, it’s a good idea to replace them. This should get your AC back to cooling like it should.

17. Exhaust Hose Blockage

When your portable air conditioner struggles to cool, it might be due to an exhaust hose blockage. This hose is vital for expelling hot air from your room. If it’s obstructed, hot air can’t escape, and your AC can’t work effectively.


  1. Inspect Hose: Examine the exhaust hose for bends or blockages.
  2. Clear Blockage: Remove any debris or kinks from the hose.
  3. Ventilation: Ensure the window or vent is open for proper airflow.
LG portable ac not cooling enough

18. Evaporator or Condenser Fan Issues

If your air conditioner isn’t cooling properly, it might be due to problems with the evaporator or condenser fans. These fans play a crucial role in the cooling process. If they’re clogged or damaged, it can disrupt the airflow and overall performance of your AC unit.


To resolve this issue, start by inspecting both fans for any obstructions or physical damage. Clear away any debris or dirt that might be blocking them. If you find that the fans are damaged, it’s essential to replace them. Additionally, regular maintenance is key to keeping these fans in good working condition. Ensure they stay clean and properly lubricated to ensure optimal performance and efficient cooling.

19. AC Unit Not Functioning

Sometimes, your portable air conditioner has simply run its course. It could be extremely worn out, damaged, or have many broken parts.


As a final option, think about getting a new AC unit if your current one refuses to work. Replacing it might be your best solution when it’s no longer functional.

Frequently Asked Questions

1. Why is my brand new LG Air Conditioner not cooling?

If your brand-new LG air conditioner isn’t cooling, start by checking the temperature setting, cleaning or replacing the air filter, ensuring proper installation of the exhaust hose, and verifying that the AC is suitable for your room size. Also, confirm there are no power or electrical issues. If the problem persists, consider contacting LG customer support or the seller for assistance or warranty coverage.

2. Why isn’t my portable air conditioner cooling?

Several reasons might be causing your portable air conditioner not to cool as expected. These include power interruptions, exposure to heat, error codes, incorrect temperature settings, slow fan speed, air leaks, or dirty filters and condenser coils. Additionally, insufficient clearance, blocked vents, refrigerant leaks, a frozen evaporator coil, or high humidity levels can also affect its cooling performance.

3. Why does my LG Portable Air Conditioner keep shutting off?

Your LG portable air conditioner might shut off due to various reasons, including overheating caused by poor ventilation or dirty filters, timer settings for automatic shutdown, power interruptions, or error codes indicating specific issues.

To fix the problem, ensure adequate ventilation, clean or replace filters regularly, check timer settings, and verify a stable power supply. If the issue persists, consult the user manual or contact LG customer support for further assistance.

4. Why does my LG Portable Air Conditioner leak water?

If your LG Portable Air Conditioner is leaking water, it may be due to a clogged or dirty filter. When the filter is obstructed, the unit may not expel moisture properly, causing it to accumulate and potentially spit water.

To fix this issue, clean or replace the filter regularly as recommended in the user manual. Additionally, ensure that the unit is level and not tilted, as this can also lead to water leakage.

5. Why does my LG Portable Air Conditioner smell?

If your LG Portable Air Conditioner has an unpleasant smell, it could be due to mold or mildew growth within the unit. This can occur when moisture accumulates in the system, providing a breeding ground for odor-causing microorganisms.

To resolve the issue, clean the air filter and condenser coils regularly to reduce moisture and prevent mold growth. Additionally, consider using a commercially available air conditioner cleaner or a mixture of water and vinegar to clean the internal components and eliminate the odor.

6. Why does my LG Portable Air Conditioner says fl?

If your LG Portable Air Conditioner displays “FL,” it is likely indicating a “Full” or “Tank Full” warning related to the internal water collection tank. This means the tank is full and needs to be emptied to allow the unit to continue functioning properly.

To resolve this, carefully remove and empty the water collection tank, ensuring it is securely reattached to the unit. This should clear the “FL” warning and allow your air conditioner to operate without interruption.

7. Why does my LG Portable Air Conditioner fill with water quickly?

If your LG Portable Air Conditioner is filling with water quickly, it may be due to high humidity levels in the room or inadequate ventilation. The unit extracts moisture from the air as it cools, and in humid conditions, this can result in a faster accumulation of water.

To fix this, ensure proper ventilation by using the exhaust hose to expel hot air outside. Additionally, you can set the AC to the Dry Mode, which prioritizes dehumidification, or consider using a separate dehumidifier to reduce excess moisture in the room and slow down the water collection rate in the AC.

8. Why does my LG Portable Air Conditioner blow warm air?

If your LG Portable Air Conditioner is blowing warm air, several factors could be causing this issue. First, check the temperature setting to ensure it’s set to a lower, cooler temperature. If it’s set too high or in fan-only mode, the AC will not cool effectively.

Second, examine the air filter; a dirty or clogged filter can restrict airflow and affect cooling performance. Cleaning or replacing the filter can help.

Lastly, make sure there are no obstructions in the exhaust hose or vents that could hinder the expulsion of hot air. If the problem persists, contact LG customer support or refer to the user manual for troubleshooting guidance.

Final Words

When you encounter the issue of your LG Portable Air Conditioner not cooling and blowing warm air, these troubleshooting steps can be your initial guide to resolve the problem. By checking the temperature setting, maintaining a clean air filter, and ensuring unobstructed exhaust pathways, you can often restore your AC’s cooling efficiency. If you have any question, feel free to comment below.

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