AC Not Cooling

Is there anything worse on a hot day than your AC not cooling? As temperatures rise, you may notice your air conditioner struggles to cool your home.

If you're having trouble with your AC not cooling, keep reading to learn more about possible causes, which problems you can solve yourself, and when to call A.B. May to get the cool air flowing again below.

Reasons The AC is Not Cooling Your Home

Low Refrigerant

Refrigerant is the key to cool air because it cools the air before it enters your home. Your unit may leak, and if there is a refrigerant leak, refilling it won't solve the problem in the long run. It's important to find the leak and fix it before adding more refrigerant, or the problem will return.

Frozen Evaporator Coil

Evaporator coils can freeze due to low refrigerant levels or a lack of airflow due to a dirty air filter. The coil will not cool the air if it's frozen. If your home isn't cooling enough or not at all, and you notice ice forming on the tubing coming from your AC unit, chances are your evaporator coil is either frozen or failing.

If this happens, turn off your system and leave the fan running. This will help melt the ice faster. Next, change out your filter for a fresh one to improve airflow. Once the ice melts and you have replaced your air filter, try turning on your air conditioner again to see if it is cooling. If not, contact an expert technician to take a look at your system.

Condenser Unit is Blocked

Most AC systems use an outdoor condenser unit. This unit has a large coil and fins inside that help blow hot air out of your home. If you turn it on and the AC's not cooling, it may be blowing hot air instead. In this case, the condenser could be blocked or clogged up.

Since the condenser unit is outdoors, dirt and debris build up on those coils and, over time, make it work harder to try and cool your home. While you may still be getting cool air, you may not be getting the most out of your system if your condenser unit is blocked even a little bit. Annual System Checks can help you know if your condenser needs cleaning.

Damaged Heat Pump

Some outdoor AC units leverage a heat pump to help heat and cool your home vs. a standalone AC unit that only cools your home. Just like the above information about your condenser unit, the same thing will eventually happen to your heat pump. If debris and dirt block it or damage it, it won't cool your home effectively. Heat pumps can also be impacted by refrigerant links, damaged coils, and more.

Undersized AC Unit

When you buy a home, it often comes with an AC unit you didn't pick or install yourself. This unit may or may not be the right size for the square footage of your home. If it's not, you may not get the cooling power you need to effectively and efficiently – you're losing money each month on utilities by using an undersized AC unit. If you suspect this is why your AC is not cooling, you need a professional HVAC assessment to determine the correct unit size to cool your home.

Dirty Filter

Warm air may also be due to a dirty air filter. Dirt and debris could be blocking airflow and hindering your AC's performance. It's important to change filters regularly for best performance. Every home is unique; the air quality, smoke, pets, and other factors all determine how often the filter needs to be changed. Depending on your situation, consider changing your filter every four to six weeks. A clean filter maximizes airflow and performance, optimizing the amount of cool air that makes it into your home.


Has your air conditioner reached the end of its useful life? Air conditioners last an average of 10-15 years with regular use and preventive maintenance. If you're unsure of your AC unit's age or have recently moved into your home, schedule a System Check or a complete System Check & Clean. Your HVAC technician is happy to share the age, the estimated energy efficiency, and other details about your AC system.

Lack of Maintenance

Annual AC maintenance is crucial for the health and longevity of your system. During an A.B. May System Check, we take a look at your entire heating & cooling system. That way, you are ready for any type of weather year-round. Technicians often spot small, fixable problems before they become large, costly, and more inconvenient. This ultimately saves you time and money in the long run.


Tips for Trying to Fix an AC Not Cooling Yourself

Here are some troubleshooting tips if you are having problems with your AC not cooling.

Check the Thermostat

Check to see if your thermostat is set to heat or auto. At the beginning of a new season, it's easy to forget to change settings. If your thermostat isn't turning on, it may need new batteries. These quick fixes cover common issues and could save you the time and expense of a service call.

A smart thermostat could significantly help and even save you extra money. It communicates more effectively with your HVAC system for more accurate readings and air conditioner performance. Some smart thermostats even alert you when the AC needs a filter change. If you have a manual or even a basic programmable thermostat, we are happy to recommend an upgrade.

Clean the Outdoor Unit

If you've neglected the outdoor unit, your system can't cool properly. Be sure to clean the unit of any debris and gently hose off all remaining dirt and mud. You can also ask our technician to clean it thoroughly during a regular System Check. If you think rodents or other foreign objects are in or stuck in your AC compressor, it's time for professional help.

Problems with your AC not cooling? Contact A.B. May in Kansas City Today

Most AC not cooling issues that pop up should be fixed by a professional HVAC technician like the team at A.B. May. If you notice issues with coolant, the evaporator coil, the compressor, or any leaks, call us today. Our team is available for 24-hour AC emergency service if necessary.