What Should I Do When My AC Not Cooling Below 75?

Cleaning an air conditioning unit with a spray bottle.

The most recent survey conducted by the U.S. Energy Information Administration shows that almost 90 percent of households in the USA used an AC unit in 2020. This figure has been steadily rising over the last 20 years. Of course, summertime is when homeowners rely on their air conditioners to keep them cool and comfortable. But wait, what should you do if your AC is not cooling below 75 degrees? In this blog post, we will discuss the common problems that can cause your AC to not cool properly, as well as some tips for fixing the issue.


  • The AC System May be Improperly Sized
  • Check the Ductwork
  • The AC’s Maintenance Might Have Been Neglected
  • Clogged or Dirty Filters
  • The Refrigerant is Leaking
  • Check the Thermostat Wiring
  • Blocked Condenser Unit
  • Tripped Circuit Breaker
  • Clogged Drain Line
  • Weak Thermostat Batteries
  • Final Thoughts


The AC System May be Improperly Sized

If you experience this issue despite having a new AC unit, the cooling capacity of your unit may not be enough. In such a case, you might want to consider upgrading to a larger cooling system. However, keep in mind that a large unit can be worse than a smaller or undersized one. Aside from the fact that it costs more, it won’t completely remove the excess humidity at home. So, it would always be best to seek help from HVAC experts to determine the right AC unit size perfect for your home.

Check the Ductwork

Are you still not getting enough airflow at home even though your AC system is running and your bills are increasing? The ductwork might be the reason for this. Chances are, it could be leaking the cool air into your home’s unconditioned areas. You are, therefore, advised to have your air ducts properly checked to see if they need insulating or sealing.

The AC’s Maintenance Might Have Been Neglected

If your once perfectly functioning AC starts acting up, pay close attention to its maintenance needs. Check if you are changing the filters on a regular basis. Have your AC system checked to ensure your registers and your return air vents are free from unwanted obstructions. You also need to have your outdoor unit thoroughly checked to ensure it does not accumulate debris buildup over time. If your unit has not received a professional tune-up in a while, then schedule one right away.

Clogged or Dirty Filters

Usually, a dirty air filter is the culprit when the AC is not cooling your home below 75 degrees. So, check your filter, especially if the outdoor temperature is lower than 92 degrees.

Air filters play an essential role in trapping unwanted things and dirt from the air before they reach your evaporator coil. However, when these filters are clogged, they end up reducing the amount of air that enters the AC unit. This results in limited cool air circulating your home, which significantly affects the overall efficiency of your AC system.

Since air filters are known to trap dirt, they instantly get clogged. So, the solution is replacing or changing the filters once or twice in one to two months. You also need to have your filter regularly checked. New ACs come with filter check lights reminding and notifying you when the filters need cleaning or replacement. However, for older HVAC units, you might need to manually keep track of when your filter has been working prior to replacement.

The Refrigerant is Leaking

A refrigerant leak is also another reason behind the AC not cooling properly. Pay close attention to the presence of frost or ice buildup anywhere in the refrigerator line. The low pressure in this line, which is caused by leak, results in lower temperature in the unit. Ultimately, this can freeze the evaporator coil. So, detecting leaks earlier and fixing them can save you lots of bucks. If you suspect any leaks in your AC system, it would be best to shut it down.

Refrigerants pose health risks, so it’s best to let licensed HVAC experts handle this. If you have older units using R-22 refrigerant, you may need a brand-new AC. R-22 got phased out two years ago and is not available anymore unless, of course, some companies have reclaimed or recycled supplies.

Check the Thermostat Wiring

Your thermostat’s bad wiring can result in various AC problems. However, the issues will still depend on the type of thermostat you have. You might want to consider checking the wirings and ensure that they are in proper order. If you recently upgraded, replaced, or changed your thermostat, note that bad wiring can cause cooling problems to your AC unit. So, remove the thermostat from the wall and re-check the wiring. As much as possible, refer to the manual for instructions. Checking the wiring designation in the control panel compartment of your HVAC for wiring reference is a better option.

Blocked Condenser Unit

A blocked condenser unit cannot deliver heat to outdoor air. This will, therefore, keep the AC system from bringing the temperature down to your set point. To prevent this issue, consistently make sure that there are no items covering your unit.

In case you notice dirt on it, clean it as soon as possible. A hose is a helpful tool in cleaning away the dirt from your condenser by means of spraying water on the unit.

Tripped Circuit Breaker

Is your thermostat permanently set up or hard-wired? Something might have stumbled and tripped on your circuit breakers. Confirm by checking your electrical board, which is commonly situated in the basement. Assuming you have all your breakers properly labeled, simply search for the one that will cover your thermostat’s location.

Remember that it isn’t always obvious when the breaker has tripped. Even if you marked it and it looks fine, you still need to do a manual check to ensure it’s completely locked in. If not, then engage it. If you didn’t label your panel, check every breaker manually and see whether they are all completely engaged.

Start by holding the breaker, and check whether it moves easily or is secured. Assuming it moves, you might want to lock and secure it by pulling down on it and pushing it back up until you hear and feel it’s secure.

Clogged Drain Line

For instance, you saw a puddle around your compressor, and it’s not from the garden hose or recent rainfall. This indicates that you may have a blocked channel line. If water in the drain pan surpasses a certain limit, your compressor will be deactivated by a float. This leads to cooling loss.

Weak Thermostat Batteries

Thermostat might be a small component of your HVAC system, but this is one of the most crucial. If your thermostat is battery-operated and it’s weak with dropped voltage, realize that this can affect the performance despite having enough juice left in the battery to power the thermostat.

Final Thoughts

If your AC is not cooling below 75 degrees, any of the reasons above can be the culprit. While you can do a DIY repair, it does not guarantee long-term efficiency and can be dangerous too. So, nothing beats the expertise of qualified professionals. On Point Service Company is one of the best companies offering air conditioner repair services. With a solid reputation in appliance repair and maintenance, you can count on them to provide a prompt and effective solution at a reasonable price.

So, book an appointment now!


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