Summer is right around the corner. You know what that means. It’s time for barbecue, beaches, and…baking in your own house? While being cooked inside your own home isn’t on anyone’s agenda, it can happen easily enough if you have an air conditioning unit that needs maintenance, repair, or replacement. Too often we have to ask ourselves what to do when the air conditioner runs constantly but doesn’t cool well.

It’s important to identify the warning signs of your A/C unit early on. One of the biggest warning signs is that it is constantly running and almost never turning off. By figuring out what is causing that problem, you can figure out how to get your air conditioning unit fixed.

Keep reading to discover some of the likeliest causes of your A/C unit constantly running!


One surprise source of a constantly running air conditioner can be the evaporator coil. If it is really dirty, this actually impedes the airflow and makes your unit work way too hard to cool your house down.

Depending on your neighborhood and where your AC is located, the coil may get dirtier much more often than you expect, sometimes in as little as two months. If you have a dirty coil, you can hire a professional to clean it. Even better, you can hire a professional to regularly service the unit, and they can prevent this from happening!


Most of the time, people imagine a constantly running A/C to be due to some kind of unexpected malfunction. In some cases, though, it may just be a sign that the unit itself is the wrong size for your particular house!

For instance, if the unit is too small, then it will constantly be working overtime to cool down all the rooms of your home. And the opposite can be a major problem, too. A unit that’s too big for your house might keep the air cooler, but the air will be moist and uncomfortable, and the electric bill will be way too high.

Bottom line? You may need to call a professional to find a new unit that is just right if you find that your air conditioner runs constantly but doesn’t cool well!


When the A/C won’t stop running, it’s understandable to blame the unit itself. Every now and then, though, the real culprit is the thermostat!

Ideally, the thermostat accurately records the current temperature and dictates when the A/C starts and when it stops. However, a malfunctioning thermostat can cause the A/C to constantly run for no real reason, making you and your family highly uncomfortable.

To test things out, place a thermometer near the thermostat and wait about an hour. By that point, their temperatures should be the same. If not, it’s time to call a professional and replace your thermostat!


Many of the problems on here require a professional in order to fix them. This is one that you can handle yourself. However, it takes a bit of elbow grease.

Clogged air filters are a major cause of the A/C working too hard because dirt and debris in the filter keeps air from flowing through. This means your system cannot properly remove humidity from the house and will just keep working overtime.

Obviously, you can replace the air filters on your own. However, let this be a lesson. If it was really clogged in the first place, then you need to change these air filters more often!


If your air conditioner runs constantly but doesn’t cool well, that means the system thinks your house isn’t cold enough yet. One possible culprit when this happens is actually air leaks or other air circulation issues!

Many of us live in old homes, and the insulation inside is equally old. That means that as the insulation breaks down even further over the years, you will be losing more and more cold air, forcing your system to constantly run.

However, you can fix this issue by properly sealing these areas and, when needed, increasing or replacing the insulation. And fixing it is basically a win-win all around, as it will drive down your electricity bills while also making your home much more comfortable.

Identifying and fixing such insulation issues is not an easy DIY project, though. Don’t be afraid to reach for the phone and call a professional!


We hate to say it because it reminds us of our own age, but one hard truth is that your air conditioner runs constantly but doesn’t cool well, it may simply be getting old. And over time, this has the potential to cause many annoying issues that will cost you a lot of time and money.

This is because even the best A/C unit is going to become much less efficient over time. That loss of efficiency translates directly to problems for you, including skyrocketing electricity bills and a house that’s too hot to be comfortable.

Unfortunately, the only way to “fix” a unit that’s too old is to replace it. And when you’re shopping around, keep in mind that those “energy efficient” labels aren’t just buzzwords. These are units that will save you money over the years and will ultimately pay for themselves!


One issue with your AC unit that may surprise you, if your air conditioner runs constantly but doesn’t cool well, has to do with the refrigerant charge. When this charge is too low, it can have a negative effect on the entire system.

A low charge is usually caused by a leak in your A/C coils. This causes the unit to work much harder to cool your home down.

Fortunately, it’s possibly to identify and fix such leaks before they become an even bigger issue. However, this isn’t a problem you should take on by yourself, as you could risk injury to yourself or damage to the unit. Instead, call a certified HVAC professional to inspect your AC unit and, if necessary, to repair it!


Most of the things on this list can be difficult to identify and even more difficult to repair yourself. That’s where professionals like us come in so you can stop asking yourself what to do when your air conditioner runs constantly but doesn’t cool well.

At One Hour Heating & Air Conditioning® of Charlotte, we specialize in all of your HVAC needs. Whether you need simple maintenance or a major system overhaul, you should give our certified professionals a call!