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6 Reasons LG Portable Air Conditioner Isn’t Cooling (+ Fixes)

Extreme heat can be awfully uncomfortable, which is why the last thing you want on a terribly hot summer day is an LG portable air conditioner that isn’t cooling. Your work, sleep, or relaxing time can be negatively affected if your portable air conditioner isn’t blowing cold air. But why would a portable LG room air conditioner fail to cool?

Your LG portable air conditioner isn’t cooling because of dirty air filters, a dirty condenser coil, a frozen condenser coil, or a thermostat with the wrong setting. Other reasons your LG portable room AC may not blow cold air include a bent or extra-long vent and some error codes.

Your LG portable AC user manual directs you to call an expert HVAC for most of the problems affecting your AC. I’d like to emphasize that your best bet is indeed to have an HVAC pro check and resolve your LG portable AC problems. But I’ll also give some troubleshooting tips for the most common LG portable AC issues that cause your AC to stop cooling.

Why LG Portable Air Conditioner Isn’t Cooling?

1. Dirty Air Filter(s)

Air supply and air filters are two inseparable dependents in an AC system. If the air filter (or filters depending on your portable LG AC model) is dirty and clogged, airflow into the AC will be reduced significantly, thereby decreasing your AC’s efficiency.

Fixing dirty LG portable AC air filter(s)

According to LG, your portable AC air filters should be cleaned every 2 weeks or more, depending on the indoor air quality. If the filters are not washable, they should be replaced with new ones.

Follow these steps to clean your LG portable AC air filters: 

  1. Switch off your portable AC and wait for it to cool.
  2. Remove the filter cover.
  3. Hold each of the filters by the handle at the top-center and pull out each of the filters.
  4. If the filters are not too dirty, blow the dirt with a vacuum cleaner attachment. If instead, they are very dirty, wash them in warm water and a little detergent. Note that you should never wash air filters in a dishwasher or use hot water or harsh abrasives.
  5. While the filters are out, remove any debris on the aluminum fence with the vacuum cleaner attachment to avoid sending the debris back to the clean air filters.
  6. Leave the filters to dry completely.
  7. Replace the filters and place back the cover ensuring that it clips in its place.

Here’s a visual demonstration of the 7 steps for cleaning your LG portable AC air filters:

2. A Dirty Condenser Coil

An AC condenser coil releases the heat produced from the AC’s cooling processes into the outdoors. A dirty condenser coil can compromise how well the byproduct heat from your portable AC is expelled from the indoor and from your AC, which means that heat stays around longer.

Also, a dirty condenser can compromise the efficiency of your portable AC’s cooling capacity, making it unable to maintain the needed air temperature and requiring the room air conditioner to run continuously.

If your LG room portable AC runs continuously, more heat is produced and the low amount of cool air does not meet the required air temperature. 

3. Fixing a Dirty Condenser Coil

Given the issues mentioned above, I strongly advise that you keep the condenser coil in your portable air conditioner free of grime and grease. 

You can do this by regularly checking it for dirt while you clean the air filters and using a condenser coil cleaner solution to get rid of the dirt. I recommend using a self-rinsing and corrosion-inhibiting option like the Nu-Calgon 4171-75 Evap Foam No Rinse Evaporator Coil Cleaner.

Nu-Calgon 4171-75 Evap Foam No Rinse Evaporator Coil Cleaner, 18 oz.

I should note that while it’s possible to do it yourself, maintaining a portable AC condenser coil generally requires the expert skill of a professional HVAC expert. 

Besides, condenser coils are quite costly and you don’t want to risk having to replace your portable AC for a spoilt condenser coil, which is what experts advise in place of replacing the condenser coil. 

So, if your LG portable AC condenser coil has issues, choose the safer option and fill out the form at the end of the article or on the sidebar of this site. You’ll be promptly contacted and connected to reliable LG HVAC experts.

4. Frozen Evaporator Coil

The evaporator coil in your LG room AC extracts heat from indoor air and adds it to the refrigerant. 

If the temperatures around your LG portable AC’s evaporator coil are extremely low, the water will condense. Consequently, a frozen evaporator coil will stop your cooling unit from venting air and no cool air will be blown. 

Fixing a frozen evaporator coil

Check first that the issue with your LG portable AC is really a frozen evaporator coil by following these steps:

  1. Switch off your portable AC and wait for it to cool.
  2. Remove the grill at the back of your AC that covers the filters.
  3. Remove the filters by holding the handle at the top center and pulling the filter out.
  4. Assess the top of the compartment to notice any frost. 
  5. If your evaporator coil has ice, leave the AC turned off to allow the ice to melt before switching it on again. 

Note that leaving the evaporator coil to defrost by itself can take many hours. You may want to speed up the defrosting process by running the unit in the FAN mode.

5. Wrong Setting on Thermostat

Portable air conditioners have an in-built thermostat to ensure the right cooling temperature is maintained inside your room. A thermostat with the wrong setting can compromise the flow of cold air.

Most portable air conditioners have a COOL, DRY, and FAN setting. To blow cool air, the portable AC should be set on the COOL option, otherwise, it will be removing humidity on DRY or just running the FAN.

Fixing a wrong setting on the thermostat

You can easily fix a wrongly set LG portable AC thermostat. Simply press the mode button to change the setting and ensure it is on COOL. The COOL light should turn on and you can then set the level of cool air that you want to be delivered to your room.

For example, if your room temperature is 70°F but your thermostat is set at a temperature higher than that, then there is no way your LG portable AC is going to cool, you’ll need to set it at a level lower than the room temperature. 

In case the thermostat seems to have a problem other than wrong settings, seek the services of a reliable portable AC technician.

6. Hot Air is Blowing from the Outside through the Vent

If your LG portable AC’s vent is wrongly installed or has leaks, it will send hot air back to the room and render the cool air from your AC equally warm or insufficient. 

Fixing a wrongly installed or leaking vent

Inspect and correct the vent using these steps:

  1. Check the end of the vent that connects to the AC and ensure that it’s securely connected and no air is escaping.
  2. Check inside the vent to confirm that no objects such as packaging material, parts of the AC, or other stuff are stuck in the vent.
  3. Inspect the duct in its entire length to ensure it has no holes or cracks.
  4. Assess the other end of the vent and ensure it is securely connected to the vent panel that lets out hot air outside the window. Make sure too that the window is well sealed with no leaks. 

See this video on how to install your LG portable air conditioner to ensure no hot air leaks.

NB: If you don’t feel up to the AC installation task or the unit is too heavy for you, have an LG AC expert assist you to install to prevent damage to the unit or injury to yourself.

7. A Displaying Error Code

Sometimes your LG portable cooling unit may not blow cold air but will instead show an error code:

P2, FL, or E5 error Code: Drain pan is full

This error code may vary with the model. But, under normal circumstances, the drain pan in your LG portable AC should never need to be emptied as the unit has a slinger fan mounted above the fan. 

This fan picks up the water and sends it to the condenser to help in discharging the heat. However, if the error code keeps coming back, the drain pan may need to be emptied.

Fixing P2, FL, or E5 error code on LG portable AC

If the error code keeps displaying and the AC is not blowing cold air, remove the drain cap and tilt the AC backward to allow any water in the pan to run out of the drain outlet.

If after draining the water the error code still keeps appearing, reset the AC following these 3 steps:

  1. Switch off the power and unplug the AC. Let sit for at least 10 seconds.
  2. Plug the AC again and switch on the power button to get the AC running.

If no water is draining or you have reset the AC but the error code keeps displaying and no cool air is produced, your LG portable AC needs to be serviced. Fill out the form at the bottom of this article and we’ll connect you to a reliable LG HVAC expert.

E3/CH03 error Code: No refrigerant

If your LG portable AC screen shows an E3/CH03 code error and is not cooling, the unit has detected the absence of refrigerant. 

Fixing an E3/CH03 error code

Do not attempt to resolve an AC refrigerant issue by yourself. Instead, shut off the cooling unit and call to request the services of an LG portable AC expert technician.

Note: There are other error codes that may present on the screen. But not all will cause your LG portable AC not to blow cold air.


  • Steve Rajeckas

    Steve Rajeckas is an HVAC hobbyist with an avid interest in learning innovative ways to keep rooms, buildings, and everything else at the optimal temperature. When he's not working on new posts for Temperature Master, he can be found reading books or exploring the outdoors.

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