AC Not Cooling Below 75

There are several possible reasons why your AC Not Cooling Below 75 degrees F. The most frequent offender is an obstructed air filter. Filters that are clogged can limit airflow, preventing the home’s air conditioner from working properly. A faulty thermostat, a compressor problem, and low refrigerant levels are other possible causes.

What is the reason that my AC Not Cooling Below 75?

1. Check the thermostat

The thermostat may be set too high. This is one of the main reasons why an AC Not Cooling Below 75.

Check the thermostat temperature setting if you find that your AC is not cooling your house as well as it should.

It may be set too high. Lower the temperature to what you want and check if it solves your problem.

2. Verify for incorrect sizing

It’s possible that an air conditioner will not reach the desired temperature because it isn’t properly sized. An undersized unit will not be able to effectively cool down large spaces because of its lack of power.

If you suspect that the wrong size of your air conditioner is causing problems, call an HVAC professional to inspect your unit and recommend the best unit for you.

3. Find leaks of refrigerant

Your AC system may need to be cooling better because of a low refrigerant level. If your AC unit is not working as efficiently as it should, this could be because of a refrigerant leak.

Look for frost, ice or condensation on your air conditioner’s coils to detect a leak. Call a technician AC to repair the leak if you suspect one.

4. Condenser coils can be dirty.

Condenser coils dissipate the heat generated by your AC system’s refrigerant. This coil can become dirty and cause your AC to work less efficiently.

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Cleaning the coil with a hose or brush is possible, but you may want to hire someone else.

5. Look for a faulty compressor

If your AC is not cooling properly, the compressor can be a problem.

Many different factors can cause a compressor to malfunction, including:


Overheating is one of the possible causes of a defective compressor. Overheating can lead to the compressor shutting down or working less efficiently. This can be prevented by ensuring the compressor is properly ventilated, and the surrounding area is debris-free.

Low Refrigerant

Low refrigerant can also be a cause for faulty compressors. Refrigerant is used to cool the air in your house. If there aren’t enough, then the compressor will overheat.

It’s vital always to check your AC for any leaks and ensure that there is enough refrigerant.

Faulty electrical wiring

A faulty electrical system can cause a compressor to malfunction. It is only a problem if your AC unit has been outdated for a long time.

You should contact a qualified AC technician to have them look it over and correct any problems.

6. Look for a frosted evaporator coil

The evaporator coil absorbs heat in the home’s air so the AC can cool it down.

This coil can freeze over and prevent your AC from cooling properly. It will also make it difficult for it to reach the set temperature.

A few factors can lead to an evaporator coil freezing over.

Filter dirty

A dirty air filter can cause airflow to be restricted and the evaporator coils to become frozen over time. It’s therefore important to clean and check your air filter regularly.

Low Refrigerant

Low refrigerant can also cause the evaporator coil in your home to freeze because not enough refrigerant is available to absorb the entire heat of the indoor air. Checking for leaks is important, as is ensuring your system has enough refrigerant.

7. Drain lines can be blocked.

Drain lines help remove the water that would otherwise freeze or damage an evaporator. This line can become blocked, and water will back up in the evaporator, causing it to damage or freeze.

If you are not confident in clearing the blockage yourself, consider hiring someone who is.

8. Airflow problems should be checked

Airflow problems could also be why your air conditioner doesn’t reach the temperature you set.

Home airflow restrictions can make it difficult for your air conditioner to cool your space. Restricted airflow can be caused by several things, including:

Dirty filters

Clogged filters cause restricted airflow. Your AC will be unable to flow air if your AC air filter becomes clogged up with dirt and dust. Regularly clean and check your air filter (roughly once a week) to avoid them getting dirty.

Closed vents

Closed vents can also cause restricted airflow. Closed vents can prevent airflow from reaching your AC system and cause it not to cool properly. Make sure that all vents are opened to ensure adequate airflow.

Obstructed ductwork

Airflow problems can sometimes be caused by leaky or obstructed ductwork. Airflow can be affected by ductwork that has kinks and holes. If this is the situation, you may have to call a professional who can inspect and fix your ductwork.


Many reasons can be attributed to why your AC Not Cooling Below 75 degrees. The problem has many possible causes, from a dirty filter to a faulty thermostat. The solutions and troubleshooting outlined here can help you get your AC working again in no time. To prevent further cooling problems, remember to maintain your AC unit regularly. It is best to consult a professional if the issue persists to prevent further damage and costly repairs.