Carrier Air Conditioner Not Cooling – What’s Wrong?

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Is your Carrier AC not cooling? Even though these units have high quality and durability, some parts could affect their overall performance. See our compiled lists of reasons why your Carrier air conditioner is not working. 

Carrier AC units that are not cooling could be due to different factors. Check the following to figure out the main problem of the unit:

  1. Air Filter
  2. Condenser Coils 
  3. Compressor
  4. Heat Pump
  5. Evaporator Coil
  6. Thermostat
  7. Fan Motor
  8. Refrigerant Leak
  9. Main Control Board
  10. Temperature Control Board
  11. Temperature Control Thermostat
  12. Thermistor
  13. Run Capacitor

Keep reading to see some of the most common causes of this problem and how to fix them. See also the tips to prevent this problem in the future.

Maintenance of conditioner with master indoors. Male hands with instruments - Carrier Air Conditioner Not Cooling - What's Wrong

The Possible Causes of Carrier Air Conditioner Not Cooling

Air ConditioningCARRIER.Air conditioning outside the building.

1. Air Filter

Problem: An air conditioner's job is to cool your home by circulating air through a system of coils and removing heat from the air. But then, if your air conditioner is not cooling correctly, the first thing you should check is the air filter.

A dirty filter blocks airflow, making it harder for the air conditioner to work smoothly. It can even lead to ice buildup on the coils, which decreases efficiency and can cause long-term damage to the unit.

Solution: Fortunately, changing the air filter is a simple and inexpensive task that most homeowners can efficiently complete. By taking care of your air conditioner and changing the air filter regularly, you can help ensure that your unit will continue to provide years of efficient cooling.

2. Condenser Coils 

The air conditioner coil is a part of the system where the refrigerant absorbs heat.

Problem: Your Carrier air conditioner may not be cooling as efficiently could be due to the dirty condenser coils. The condenser coils are responsible for releasing heat from the refrigerant. So, they won't be able to do their job correctly if dirt and debris are covering them.

Solution: To clean the coils, simply remove them from the unit and brush away any dirt and debris. You may also need to use a commercial coil cleaning solution to remove any stubborn build-up.

Once the coils are clean, reattach them securely before turning the unit back on. With clean condenser coils, your Carrier air conditioner should be able to cool your home more effectively.

Use coil cleaning for your AC.  See it on Amazon.

3. Compressor

Problem: The compressor is responsible for circulating refrigerant through the system. If it's not working, the refrigerant can't do its job, and your home won't get cool.

Solution: If you suspect that the compressor is the problem, make sure there is the power to the unit. If the unit isn't getting power, the compressor won't run.

Next, check the compressor itself for signs of damage. If you notice some damage to the compressor, you need to replace it now.

4. Heat Pump

Air Conditioning Technician and A part of preparing to install new air conditioner. Technician vacuum pump evacuates and checking new air conditioner

Problem: One of the most common reasons a Carrier air conditioner doesn't cool is because the heat pump has frozen. The heat pump is responsible for transferring heat from inside the home to the outdoor unit.

When the outdoor temperature drops, the moisture in the air can cause the coils to freeze. It can happen even if the temperature isn't that cold. 

Solution: The best way to prevent this is to keep the area around the outdoor unit clear of debris and ensure it's covered when it's not in use. If you find that your heat pump has frozen, you can try turning off the power and thawing it out with a hairdryer. You should also check the thermostat to make sure you set it properly.

5. Evaporator Coil

Air conditioning service, repair & maintenance concept. closeup at an indoor unit coil.

Problem: The coils are responsible for transferring heat, so it might cause problems if they are getting too much dirt and dust.

Solution: To clean the coils, simply remove them from the unit and brush away any dirt and debris. You may also need to use a commercial coil cleaning solution to remove any stubborn build-up. Similar to other coils, place them again before turning on the AC.

6. Thermostat

Problem: If the thermostat is not set high enough, your air conditioner will not turn on, and your home will not get cool.

Solution: To ensure that your Carrier air conditioner is cooling as efficiently as possible, make sure you adjust the thermostat setting at least five degrees higher than the current temperature in your home. In addition, make sure that the thermostat is in the cooling mode and not the heating mode.

7. Fan Motor

Close up of an HVAC unit motor belt drive

Problem: One of the most common issues with a Carrier air conditioner is that the fan motor could stop working. If this happens, the entire system will need to be inspected by a professional to determine the cause. In some cases, the problem may be as simple as a loose wire or blown fuse. 

Solution: If you suspect that the fan motor is not working correctly, there are a few things you can check. First, check the unit is on. If the fan motor isn't running, it won't be able to cool your home. Next, check the fan motor for signs of damage. If it is now totally damaged, you must replace it.

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8. Refrigerant Leak

Problem: Another issue could be due to a refrigerant leak. Refrigerant is the substance that helps your AC unit cool the air, so if there's a leak, the unit won't work correctly. A few signs that you may have a refrigerant leak include ice buildup on the evaporator coils or hissing noises coming from the unit.

Solution: If you suspect that your AC unit has a refrigerant leak, it's essential to call a professional for repair service right away. Refrigerant leaks can damage your AC unit and can also be unsafe if not handled properly.

9. Main Control Board

Problem: The carrier air conditioner will stop cooling could be due to a failing control board. The control board is responsible for supplying power to the compressor and fan, so when it fails, those components will not be able to run.

Solution: In some cases, you may be able to replace the control board simply, but in other cases, you may need to replace the entire air conditioner.

10. Temperature Control Board

Problem: The temperature control board manages the tension in the coils and valves to create cold air.

Solution: If there is an issue with the board, you may need to replace it to get the unit working again. Replacing the temperature control board is not a difficult task, but it is best to reach out to a professional.

11. Temperature Control Thermostat

Air conditioner remote control with smart home system on digital device.

Problem: Another one to blame is the temperature control thermostat. This thermostat is responsible for regulating the temperature inside the unit, and if it isn't working correctly, it can cause the unit to overheat or cool down too quickly.

Solution: First, check the batteries in the thermostat and replace them if necessary. Next, clean the sensors on the thermostat with a cotton swab dipped in rubbing alcohol.

If the problem persists, you may need to replace the thermostat itself. Fortunately, this is a relatively easy repair that you can complete in a few minutes. With a new thermostat in place, your Carrier air conditioner should be able to cool your home efficiently.

12. Thermistor

Problem: A thermistor is a temperature-sensitive resistor used to measure temperature. It typically has semiconductor material, such as carbon or silicon. The resistance of a thermistor decreases as the temperature increases.

Solution: Check the thermistor for continuity. If there is no continuity, you should consider changing the thermistor. If there is continuity, the problem may be with the air conditioner itself.

13. Run Capacitor

Problem: A capacitor is an electrical device that helps to store and release energy. When the air conditioner is on, the capacitor provides a surge of power to the compressor, which gets the cooling process started.

Over time, the capacitor will become more damaged or worn out. If this happens, it can prevent the compressor from starting up, which will cause the air conditioner to stop cooling.

Solution: First, check the voltage across the capacitor terminals. If the voltage is low, the capacitor is not working properly. Second, measure the capacitance with a multimeter. If the capacitance is low, the capacitor is not working properly.

Finally, check for signs of physical damage to the capacitor, such as cracks or leaks. If you find any damage, the capacitor needs to be replaced. 

Change your run capacitor. View it on Amazon.

If you’ve checked those things and your air conditioner is still not cooling, what do you do? 

Maintenance of conditioner with master indoors. Male hands with instruments.

If you feel confident in fixing things yourself, you can simply follow the tips mentioned earlier.

But then, if you’re not sure what’s causing your air conditioner to stop cooling, it’s best to call a certified technician for diagnosis and repair. A qualified technician will be able to diagnose the problem and make the necessary repairs quickly and efficiently.

What are some ways to prevent my Ccarrier air conditioner from not cooling properly?

Regular maintenance is the key to helping prevent your air conditioner from not cooling properly. Here are a few things to follow:

  1. First, make sure to keep the unit clean and free of debris.
  2. Next, check the filters regularly and replace them when necessary.
  3. Finally, be sure to schedule regular maintenance appointments with a qualified technician.

By following these tips, you can help keep your Carrier air conditioner running smoothly all summer long!

Final Words

If your AC unit is not cooling, it’s vital to take action sooner rather than later. Remember, a broken air conditioner can lead to uncomfortable temperatures and a hefty energy bill. So, keep them nice and clean to get the most out of your AC unit!

To get more details on how to maintain your AC, check out the following articles below:

Why Is My Air Conditioner Frozen Inside?

Why Is My Trane Air Conditioner Leaking Water?

Air Conditioner Turns Off After 30 Seconds – What’s Wrong?

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