Keep It Cool: Why Is My AC Running but Not Cooling?

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Keep It Cool: Why Is My AC Running but Not Cooling?


There are few things more frustrating than coming in from the heat to find your AC blowing warm air. When you’re looking forward to a cool home, the last thing you want is desert-hot air that’s arid enough to dry your hair!

Before you pull out your floor fans or a portable AC, you might want to take some time to troubleshoot your central air system. In many cases, you’ll find that strategies as simple as cleaning or dusting can get your air conditioner back up and running.

Ready to figure out the culprit behind your faulty AC? We’ve got you covered! Read on to learn why your air conditioner is blowing hot air.

Your Thermostat Is Inaccurate

In some cases, the fault may not be with your air conditioner but with the thermostat itself. If your thermostat is on the wrong setting, you may find that your AC is blowing air like a fan rather than cooling the air it circulates.

Check to make sure that your thermostat is on and set to cooling mode.  From there, wait to see whether cool air begins filtering from the registers.

You’re Experiencing Electrical Issues

Are you sure power is flowing to your outside unit? If your AC has blown a fuse, or if you’re experiencing electrical issues, it’s possible that your AC isn’t running as it should. Check your breaker box to see if any fuses have been flipped.

Your Filter Is Dirty

It may come as a surprise to learn that your air conditioner’s filter has a larger role to play than keeping particles out of your indoor air. In fact, something as simple as a clogged filter can wreak havoc on your entire HVAC system, forcing your unit to struggle to cool your home. It can even cause your home and your AC system to overheat.

There’s a reason experts advocate replacing your filter at least once every month or so, depending on your household! Turn off your AC and replace your dirty air filter with an option with a high MERV rating, or clean your filter if it’s reusable.

Your Ducts Are Leaking

Are you sure your cool air is staying where it belongs? If your air ducts are damaged or broken, your precious conditioned air may be escaping into an unwanted area.

It can be hard to tell on your own if you have an air duct leak. However, in some cases, you might notice excessive dust in certain areas of your home, a sign of a broken or outdated duct. An AC expert can take a look at your system to let you know whether you need duct repair or replacement.

Your Condenser Coil Is Clogged

Your exterior condenser unit has a coil that stretches around your system. If this coil has become clogged with debris, it can cause the entire system to malfunction.

To check for a clog, head outside to take a look at this equipment. You’ll want to look for dirt, grass, leaves, or other foreign contaminants. If you spot anything, clean it away with care using a brush or a hose.

Your Evaporator Coil Is Frozen

Head back inside to check the indoor component of your central air. Here, you’ll want to check your evaporator coil, which is what helps your air conditioner remove thermal energy and pump cool air back into your home. In some cases, this coil can malfunction and begin to freeze, which can ironically cause your system to stop producing cool air as usual.

Depending on your air conditioning unit, you may find your evaporator coil outside of your furnace in a separate drawer. For units with a fan coil, you’ll find it inside the main cabinet. Check for signs of frost or ice on the tubing, as well as more condensation or drainage than usual. In serious cases, you may even see a puddle beneath the coil.

While you may be able to spot signs of this damage on your own, this is one type of AC repair you’ll want to leave to the professionals.

Your Refrigerant Is Leaking

During the cooling process, refrigerant is what allows your air conditioner to cool down warm air. Changing from a liquid to a gas and back again, it passes between your outdoor and indoor coils to transport warm and cool air back and forth.

A refrigerant leak can throw your air conditioner off balance, making it struggle to keep your home cool. You’ll want to check for signs of leakage around both your indoor and outdoor unit.

However, make sure not to try dealing with this leak on your own. Refrigerant is hazardous to handle or inhale, so be sure to call for expert backup!

Your Heat Pump Is Damaged

If you have an outdoor heat pump, you may find that it’s prone to some of the same issues above, like clogged or frozen coils, thermostat errors, clogged filters, or refrigerant leaks. If you’ve exhausted the options above, head out to your heat pump and check it for the same things your AC unit might struggle with. If you notice any issues, reach out to a professional who can repair your system.

Get Your AC Back Up and Running Fast

If you’re tired of the balmy air circulating around your home, it’s time to get your AC back up to speed. The tips above can help you troubleshoot some of the most common problems when it comes to an AC that’s blowing hot air, so check your indoor and outdoor units to see what’s going on.

Still not sure of the cause? If you need professional assistance, our team is here to help.

As the trusted AC repair and maintenance source for homeowners throughout South Carolina, Cool Care Heating and Air will get the job done. Learn more about what we can do, and reach out for a quote today.