LG Portable Air Conditioner Compressor Not Working (11 Fixes!)

Sometimes when an LG portable air conditioner overheats or fails to cool, the issue is often a faulty compressor. But what are the reasons for an LG portable air conditioner compressor not working?

An LG portable air conditioner compressor will keep shutting off due to overheating, dirty filter or condenser coils, burnt overload, damaged or blocked suction line, low refrigerant, wiring fault, or shorted compressor. 

On the other hand, the compressor may refuse to turn on if it’s defective or due to power failure or a faulty compressor-linked component such as the temperature control board, thermostat, capacitor, thermistor, selector switch, start relay board or main control board.

So, there are two issues to look at when it comes to a compressor malfunction. On the one hand, we have an AC compressor that won’t turn on. On the other hand, we have a compressor that keeps shutting off after powering on. 

To clarify, I’ll discuss the two sets of issues and their fixes. But first, what is the AC compressor, and how do you know it’s not working? Let’s answer that.

LG portable air conditioner compressor not working

In a hurry? Check below the likely causes of an AC compressor failure, plus the applicable fixes.

Quick Troubleshooting Guide for an LG Portable Air Conditioner Compressor Not Working.

(Air Conditioner Compressor Keeps Shutting Off)
Likely Cause  Recommended Fix 
1. Overheating  Turn off the AC briefly to cool it down
2. Dirty filter  Change the air filter if it’s dirty
3. Dirty condenser coils  Clean the condenser coils if dirty
4 Burnt overload  Replace the overload if it has no continuity
5. Damaged /blocked suction line  Request an expert inspection 
6. Low refrigerant  Request an expert inspection of the AC
7. Wiring fault  Consult a professional (electrician)
8. Shorted compressor  Replace the compressor 
(Air Conditioner Compressor Won’t Turn On)
Likely Cause  Recommended Fix 
9. Defective compressor  Replace the compressor if it fails the compressor test
10. Power failure  Reset the breaker and replace the unit’s fuse if it lacks continuity
11. Faulty compressor-linked component  Replace the temp control board, thermostat, capacitor, thermistor, selector switch, start relay board, or main control board if faulty

What Is the Compressor and What Does It Do On an LG Portable Air Conditioner?

The compressor is a part of the air conditioner or HVAC system that compresses the liquid coolant or refrigerant to enable the air conditioner to run, cool, and heat uniformly.

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How Does an LG Portable Air Conditioner Compressor Work? 

The compressor performance starts from the refrigerant. The refrigerant absorbs heat from the surroundings and flows to the AC compressor, where the compressor converts it into liquid (it compresses it). 

Once compressed, the refrigerant temperature rises, turning it into high-pressure gas. The high-pressure gas then flows to the AC’s condenser coil, where it releases the heat. 

The gaseous refrigerant then converts into a liquid state and flows back to the indoor unit, and the process repeats. 

How to Identify a Faulty LG Portable Air Conditioner Compressor? 

There are two tricks for recognizing when your LG portable air conditioner compressor is not working. First, you can look for the signs of a defective compressor based on the air conditioner’s performance.  

Second, you can perform a compressor test. Let’s look at the two:

Signs of A Faulty LG Portable Air Conditioner Compressor 

You can know if your LG ACs compressor is faulty if it shows a majority of these signs:

  • Weak airflow (little or no airflow)
  • A strange noise, particularly a loud bang
  • Leaky refrigerant (which you can tell from a hissing sound, wetness around the AC, or frosting over the evaporator coils)
  • Burnt rubber smell
  • No humming sound from the compressor when turned on 
  • The AC failing to cool
  • Overheating
  • Hard restart by the air conditioner (the AC keeps going off after starting)
  • Tripping breaker
LG portable air conditioner compressor not turning on

The Compressor Test

You can also perform the compressor test to determine if your air conditioner compressor is faulty or if the problem is something else.

Here are the steps for doing it:

  • Unplug your portable air conditioner for 30 seconds or more 
  • Plug the AC back into the power and turn it on
  • Set the thermostat setting on Cool Mode, the highest fan speed or the lowest temperature
  • Carefully listen to the compressor turn on (it usually takes 30 seconds or more)
  • The compressor is okay if you hear it running (producing a humming sound).

If the compressor is not faulty, look for other reasons possibly preventing the compressor from working. Those are the issues I highlighted in the earlier table, which I will also discuss shortly. (Tramadol)

But what if you can’t hear the compressor making a humming sound? Then replace the compressor. But since the replacement can be technical and expensive, request an expert technician service. 

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LG Portable Air Conditioner Compressor Keeps Shutting Off

Now, consider these eight issues if your LG portable AC compressor starts but won’t run for long:

1. Unit Overheating

The compressor mostly shuts off after it overheats as a precautionary measure to protect it and the AC. It’s usually a sign that the compressor and the air conditioner are overworking.

Thus the air conditioner needs a rest. But sometimes, the compressor may overheat because of a low refrigerant or dirty coils. So, you cannot overlook the two issues.


Turn the air conditioner off to give the compressor a rest. Once the AC cools down, power it on but if it overheats again and the compressor goes off, check for possible dirty coils or low refrigerants and fix them as I explain in numbers 3 and 6.

2. Dirty Filter 

The air filter may accumulate dirt over time. Once that happens, the compressor doesn’t get enough air, forcing it to shut off. Sometimes the compressor won’t turn on as a result. 


Consider changing the air filter if it’s dirt-clogged. Alternatively, clean it if it’s not heavily clogged.

3. Dirty Condenser Coils 

Dirt, dust, and grime can clog the condenser coils. And when they do, they compel the compressor to work extra hard.

As explained earlier, the compressor eventually overheats and shuts down to protect itself. That’s why cleaning the condenser coils as often as the filter is advisable.


Inspect the condenser coils for dirt clogging and clean them. 

LG portable air conditioner compressor keeps shutting off

4. Burnt Overload 

The overload’s role is to protect the compressor during an overcurrent (or power surge). Due to excessive current or power surge, the overload burns out, and when it does, it’s unable to protect the compressor. 

So, the compressor may get short-circuited and fail to turn on. 


Using a multimeter, determine if the overload has continuity. If it doesn’t, confirming it’s faulty, replace it. 

5. Damaged or Blocked Suction Lines

For the refrigerant to flow through the AC system, the suction lines should be free from cracks, holes, and any other forms of damage. Likewise, the lines shouldn’t be dirt-clogged. 

If they are damaged or blocked, the refrigerant won’t reach the compressor to be compressed, and the compressor will therefore shut off. 


Request an expert inspection of the suction lines if you suspect they might be damaged or blocked. 

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6. Low Refrigerant 

The compressor is unable to run when the refrigerant level drops. Remember, a low refrigerant level is one of the reasons the air conditioner overheats and causes the compressor to go into a self-shut mode. 

So, it’s essential to identify the signs of a refrigerant leak, which include the following:

  • Hissing sound
  • Frosted over coils
  • Wetness around the AC


Once you identify the above signs of refrigerant leakage, request an expert inspection. 

7. Wiring Fault

If there’s an electrical or wiring fault, the compressor won’t get sufficient power and will shut off. So, you may need to check the other electrical appliances to see if they are working.


Once you suspect a wiring fault (when all the other appliances won’t work), request an expert inspection of your electrical wiring.

8. Shorted Compressor 

In a worst-case scenario, the compressor itself could fail from short-circuiting. That’s likely to happen during an electrical fault or power surge. But due to the presence of the fuse, the overload, and the breaker, it’s less likely to happen. 


Perform the compressor test and replace the compressor if it fails the test. 

LG portable air conditioner compressor not coming on

LG Portable Air Conditioner Compressor Not Turning On

If your portable AC compressor won’t power on and run, it’s likely to be because of one of these three reasons:

1. Defective Compressor 

The reason why your compressor won’t turn on could be because it’s defective. Also, note that a bad compressor could be why your portable air conditioner won’t turn on entirely.

Not only should you look for signs of short-circuiting or burn but also wear. Even better, you can perform the earlier discussed compressor test to know if the compressor is defective. 


Replace the compressor if it fails the compressor test.

2. Power Failure (Power Supply Failure)

Your AC compressor won’t turn on if there’s a power failure. That includes the following situations:

  • A power surge that trips the breaker or blows up the thermal fuse
  • Power outage


While there’s nothing to do in case of a power outage, you’ll need to reset the breaker if it’s tripped. As for the fuse, test it with a multimeter to determine if it has continuity. If it doesn’t, replace it. 

3. Faulty Compressor-Linked Component

The running of the compressor depends on several components. Once one of these components fails, the compressor won’t turn on, and if it does turn on, it’s likely to shut off.

These compressor-linked components include the following:

  • Temperature control board
  • Thermostat (or temperature control thermostat)
  • Capacitor
  • Thermistor 
  • Selector switch 
  • Start relay
  • Relay board
  • Main control board


If any of the compressor-linked components is faulty, replace them. You may, however, need professional help to diagnose and replace them.

Closing Thoughts On an LG Portable Air Conditioner Compressor Not Working:

Now you know what to look into when your LG portable air conditioner compressor doesn’t work. That includes when the compressor won’t turn on or when it turns on but keeps shutting off. So, use the above LG portable air conditioner troubleshooting guide to get your AC compressor running smoothly.  

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