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Portable Air Conditioner Compressor Keeps Shutting Off: What To Do?


A portable air conditioner is one of the appliances in our room that makes us feel relaxed because of its cooling process. However, there are instances where the portable air conditioner compressor keeps shutting off. 

If you want to know the answer to why this happens and what to do, just keep reading this article to find out the solution to your AC problem.

What is a Portable Air Conditioner Compressor?

portable air conditioner compressor keeps shutting off

Responsible for compressing and circulating refrigerant in the vapor compression cycle, an air conditioner compressor is a standard component of a typical aircon unit. It is usually located inside the main body of the compressor and is typically powered by electricity. 

The compressor compresses low-pressure refrigerant gas and converts it into a high-pressure gas, which is then passed through the evaporator. The refrigerant absorbs excess heat from the air inside the room as it passes through the evaporator, providing cool air in the process. The cooled refrigerant is then returned to the compressor, where the process is then repeated.

What Does a Portable Air Conditioner Compressor Do?

The compressor inside the compressor unit is liable for maintaining the proper pressure and temperature differences required for the air conditioning process to work effectively. It is also responsible for circulating the refrigerant throughout the system, ensuring that the AC unit can absorb heat from the air in the room and release it outside.

If the compressor is not functioning correctly, like shutting off suddenly and continuously, the portable air conditioner’s cooling capacity can be severely restricted.

Why Does My Portable Air Conditioner Compressor Keeps Shutting Off?

The repeated shutting off of a portable AC is called short cycling. Short cycling occurs when the cooling cycle becomes shorter than the usual 10 minutes of AC, causing the compressor to turn on and off more often than usual.

So with that, there are some reasons why your portable air conditioner compressor keeps having a short cycle and shutting off frequently, like the following:

  • Dirty air filter
  • Clogged condenser coil
  • Leaking refrigerant
  • Faulty compressor 
  • Faulty thermostat
  • High compression ratio
  • Loss of refrigerant
  • Incorrectly fitting components
  • Low suction pressure

How Do I Stop My Portable AC Compressor From Shutting Off?

To stop your portable air conditioning unit from shutting off, here are a few things you can try to troubleshoot the issue:

Examine the Air Filter

Make sure the air filter is clean and unblocked. Air conditioners usually have these on the front of the side, located behind a removable panel. A blocked or dirty filter can result in restricted airflow, causing the compressor to shut off, your evaporator coils to freeze, or clogging your condenser coils.

To ensure adequate airflow, the dirty filter should be washed or replaced. Also, be sure to get the correct size and type of filter for your portable AC unit to avoid further problems. 

Check the Thermostat Settings

Usually located on the control panel of most portable air conditioners, the thermostat should be easy to identify. Check the thermostat for any visible signs of damage. If the thermostat is damaged or has any loose wires, it may not be functioning properly.

Check the settings and test the thermostat. Ensure that it has a set temperature lower than the room temperature to trigger the compressor to turn on. Try doing this in a relatively small room in order to test it quickly. If the compressor does not turn on, there may be an issue with the thermostat, or you might have inputted the wrong settings.

Find Any Leaks in the Air Ducts

In a portable AC system, air ducts could be located behind the unit or within the air conditioning system itself.  A leak can cause the compressor to shut off due to a loss of pressure, disrupting the air conditioning cycle.

On inspection, ensure that the air ducts do not have any holes, cracks, or openings that could be causing leaks. In the absence of openings, check the seals and ensure they are secured and undamaged. 

Finally, check the connection points between the air ducts and the unit. Loose connections could result in a noticeable loss of airflow or the air conditioner not cooling effectively.

Make Sure the Unit is Properly Sized

If you use your most portable AC unit, but its compressor continues to shut off, it may be too small for the room, as it will have to work harder to cool the space and maintain your set temperature. 

Check the manufacturer’s recommendations, as most portable AC units have information on the box or in the user manual about the recommended size of the room.

If your portable AC seems to have an insufficient cooling capacity for your room, you could try using a central air conditioner instead, as they are typically more efficient and effective at cooling larger spaces than other types of air conditioning systems, such as window units or portable air conditioners.

Look for Any Ice Build-up on the Evaporator Coils

Check behind the removable panel of the portable AC and look for any ice or frost on the evaporator coils, as frozen evaporator coils can cause the compressor to shut off.

Also, make sure to check the refrigerant level, as a low refrigerant level could result in frozen evaporator coils, effectively disrupting your unit’s cooling system. A dysfunctional evaporator coil could be the reason why your portable AC turns off repeatedly.

Check Your Portable AC’s Condenser Coils

Behind or under your portable AC, look for any dirt, debris, or blockages, as they are typically the cause of clogged condenser coils. Clogged coils usually generate excess heat, causing your air conditioner compressor to shut off.

Like the evaporator coil, check for refrigerant leaks. If the refrigerant level is low, it can cause the condenser coils to become clogged.

Using a coil cleaning solution or a soft brush can help to remove dirt, debris, and other contaminants from the condenser coils, improving the unit’s efficiency and performance.

Ensure the Unit is Properly Vented

If the unit is not venting properly, it can cause the compressor to shut off. First, check the vent covers and ensure they are open and not blocked by any furniture or other objects.

Next, check if the vent ducts are properly connected and not damaged or leaking. Lastly, check for any clogged components in the vent system, like the vent registers. Blockages and clogging could restrict airflow and disrupt the venting process.

Look For Any Damaged or Frayed Wires

If any of the electrical wiring is damaged, it can cause the compressor to shut off from poor electrical connections. Nothing feels worst than trying to fall asleep and hearing your portable AC shut off suddenly because of an electrical problem.

Before inspecting the wires, turn off the power to the unit and unplug from any power sockets to avoid being shocked by or damaging any electronic components. Look for any wires that are damaged or frayed, such as wires with exposed wire strands or wires that are coated with insulation that is cracked and peeling.

Electrical wiring problems could also result from poor and loose wire connections. Make sure that all of the wire connections are secure and not loose to ensure continuous power to your unit.

Check for Any Faulty Relays

Used to control a circuit or device by turning it on or off, a relay is an electrical switch that is one of your unit’s electrical components that is controlled by an electromagnet. A faulty relay may cause issues with the circuit or device it controls.

A faulty relay can cause various issues to your unit’s power supply, such as an appliance or device not turning on or off as expected, an appliance or device not functioning properly, or an appliance or device making strange noises.

Check the relay located within the control panel of your portable AC unit. Make sure that the connections to the relay are secure and that any wiring to the relay is not damaged or frayed.

Insufficient Refrigerant

Insufficient refrigerant in a portable AC refers to a situation in which there is not enough refrigerant in the system to cool the surrounding temperature effectively. Refrigerant is a vital component of an AC, as it, along with the cooling coils, absorbs heat from the air inside the unit and releases it to the outside air. 

If there is insufficient refrigerant in the unit, it can affect the unit’s performance and efficiency during its normal operation. Several causes could be refrigerant leaks, improper installation, or manufacturing defects. In addition, refrigerants could be introduced to the unit in small quantities in the suction line after a fixed leak.

Check Your Unit’s Vent Hose

Typically made of durable and heat-resistant material, a vent hose is a flexible tube that is used to vent exhaust from your AC to maintain an adequate temperature inside your room. Usually connected to the back of the unit and secured with a clamp or other fastener.

Check the vent hose for any visible signs of damage, such as holes, cracks, or punctures. Afterward, check that the routing of the hose is routed correctly and not kinked or crushed.

Final Thoughts

There are many possible reasons why a portable air conditioner compressor might keep shutting down, and it’s important to identify and fix the issue as soon as possible to ensure the unit is functioning properly. Whether it’s a problem with the thermostat, the refrigerant level, or something else, you can take steps to troubleshoot and fix the issue.

After all, why buy a new portable AC when you could just fix the old one?

If you have tried these troubleshooting steps and your portable air conditioner’s compressor is still shutting off, it might be a good idea to have an HVAC technician look at a possibly faulty compressor unit.

JP Reyes

JP has been in the aircon industry for almost as long as he has been alive. As a child JP would help his tatay fix aircon units at their junk shop in Cavite. After graduating UP in the early 2000's, JP then started his own Aircon servicing business and within 5 years had 10 shops in 8 different cities. Fast forward to today and JP brings all his experience and expertise online to give readers trustworthy advice and reviews about Air-conditioning buying, servicing, cleaning and repair in the Philippines.

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