ABC Blog

My AC Is Running but Not Cooling

an air vent

Your AC is expected to cool down your home and provide comfort during hot and humid days. But it doesn’t always work that way. If your AC is running but not cooling, it will leave you hot instead of calm and collected. Unfortunately, this is a common problem homeowners face, and there are many possible reasons behind it.

Something is amiss inside your AC if it can no longer do its job. Here are some ways to find the culprit and troubleshoot the problem. However, most AC issues are complex and require the expertise of a pro. If you’re not confident in your DIY skills, it’s better to let an HVAC specialist take over. They can perform the necessary repairs and replacements and have your unit running smoothly again.

What To Do If Your AC Is Running But Not Cooling

ACs have intricate systems. One malfunctioning part can lead to the entire unit’s breakdown. If your AC is running but not cooling, something is wrong with the coils, air filter, thermostat or another critical part.

Here are some steps to get to the bottom of the issue.

Correct the Thermostat Setting

If your AC isn’t blowing cold air, the solution can be as simple as adjusting the thermostat. Check that it’s on the “cool” setting and that someone didn’t accidentally change the temperature. If it’s off or set in “heat” or “constant fan” mode, turning it on and putting it on the correct setting should do the trick.

Wait a few minutes for the system to warm up, then check if it’s blowing cold air again. If not, proceed to the other troubleshooting methods.

Clean the Condenser Unit

The condenser is your AC’s outdoor unit. It features a massive outdoor coil with tightly spaced metal fins. Its primary role is to extract the heat inside your home and release it to the outside. Unfortunately, the condenser tends to accumulate dirt and debris over time. It’s not unusual to see leaves, grass and twigs in there.

A dirty or clogged condenser coil leads to lower energy efficiency. Your unit has to work much harder to cool your home. The worst-case scenario is complete compressor damage or system shutdown. You can prevent this by gently rinsing the condenser coils with a hose. Better yet, have them professionally cleaned by an HVAC specialist.

Unfreeze the Evaporator Coil

The evaporator coil is part of your AC’s indoor unit. The system passes the warm air inside your home over the evaporator coil to remove its heat and humidity. Your unit will then blow the air back into your home, only it will be cool and refreshing this time.

However, some things can restrict the airflow inside your AC, like clogged air filters or clogs in the drain. With insufficient air and heat, there’s nothing to prevent the condensation on the evaporator coil from becoming ice. The result is a frozen evaporator coil and an AC that won’t blow cold air. You might also experience soaring utility bills.

While homeowners can try unfreezing their evaporator coil, it’s hard to access. It’s better to sit back and let a professional do the work. An HVAC specialist will remove the ice on the coil and ensure your unit gets sufficient airflow.

Clean the Air Filter

Your AC’s air filter plays a crucial role. It traps dirt, dust and debris, keeping the other components clean and efficient. It also ensures you get clean air inside your home. However, it can become clogged over time, hampering the airflow inside the AC. That can cause your unit to overheat, unable to relieve you with cold air. The system might even shut down entirely.

Keep the air filter clean to help your AC perform at its best. Clean or replace it every three months to prevent dirt and debris buildup. You might have to do so more often if you have furry family members.

Fix the Refrigerant Leak

You can’t enjoy cool air in your home without refrigerant. Refrigerant flows through your AC’s indoor and outdoor units, absorbing heat and releasing it outside. If you have a refrigerant leak, it’s important to call a professional for help. Refrigerant leaks can be dangerous, which is why it’s important to trust an HVAC professional to help.

Refrigerant leaks aren’t something you should try to fix on your own. If you suspect you have one, contact HVAC professionals so they can deal with the situation. They will either patch up the hole or replace the pipe altogether.

Get the Correct AC Size

If your AC is undersized for your home, it will struggle to fill the space with cold air. It has to work harder and longer to achieve your desired temperature and will eventually strain itself. This issue is much more noticeable on hot days. One possible fix is to install a ductless AC unit to help share the load. You can also replace your existing unit with the correct size.

However, determining the right AC size isn’t always easy. There are various things to consider, like the local climate, your home’s insulation and square footage. An HVAC specialist can help you assess your space and find the best AC size for your home.

Reset the Breaker

If your AC refuses to run entirely, you might be dealing with a tripped breaker. Head to the breaker panel and locate your AC’s breaker. Flip it off and then on again to reset it. If your AC still doesn’t want to turn on after the reset, there’s a more complex underlying issue. That needs the attention of an HVAC professional.

A homeowner’s DIY skills can only do so much when their AC is running but not cooling. While you can clean the air filter and adjust the thermostat setting, the other troubleshooting methods require more technical experience. Instead of sweating it, relax and let an HVAC specialist take care of your AC woes.

an AC unit

What To Do if Your AC Compressor Is Humming but Not Starting

Another issue many homeowners encounter is an AC compressor that hums but won’t start. The compressor plays a crucial role in the AC system, pressurizing the refrigerant and increasing its temperature. It then reverses this process to complete the cooling process.

There are various possible reasons behind a compressor that won’t start, but the capacitor is the most common culprit. Your AC’s capacitor stores energy to provide the compressor with an extra boost during startup. Aside from the compressor, the capacitor also powers the outdoor fan and blower motor. If you hear a humming, that’s probably the compressor trying to get power from a failed capacitor.

If you’re in this situation, turn off the AC to keep the compressor from overheating. Ignoring the humming can cause a simple capacitor problem to snowball into a costly compressor failure. Next, contact an HVAC professional to do a capacitor replacement.

a living room

What To Do if Your AC Turned Off by Itself and Won’t Turn On

If your AC has turned off by itself and won’t turn on, don’t panic. There might be a simple explanation for the disruption. Here are some possible reasons behind this issue and what you can do.

Adjust the Thermostat

The first step is to check the thermostat. It may be in the wrong mode or temperature setting. Ensure it’s on and on “cool” and that the temperature is lower than the ambient temperature in your home. If that doesn’t work, it might be time to replace the batteries. If fresh batteries don’t solve the issue, your thermostat might need a replacement. Contact an HVAC specialist to install a new one for you.

Replace the Air Filter

If you can’t remember the last time you replaced the air filter, that’s probably why your AC won’t start. A clogged air filter hampers airflow and affects the unit’s performance. You can prevent AC issues by replacing the air filter every three months. You should change air filters more often if you have pets or live in a high-pollution area.

Check the Breaker

If your AC has turned off by itself and you can’t get it to run again, the circuit breaker might have tripped. Head to the breaker panel and check if your AC’s breaker is in the “off” position. Flip it back on, and your unit should come back to life. If the breaker keeps tripping, there’s a more complex underlying problem, and you should contact an HVAC professional.

Leave Your AC Troubles to the Pros

Sometimes, a simple air filter replacement or a thermostat adjustment is all it takes to resolve an AC issue. But other times, the problem is too complex to fix with DIY skills. Leave issues like refrigerant leaks, compressor failure and frozen evaporator coils to the pros. An HVAC specialist will provide the best solution and have your AC in tip-top condition again.

ABC Can Keep Your AC Working Efficiently

Dealing with AC issues requires lots of technical know-how. Instead of trying to figure it out yourself, contact ABC Home & Commercial Services. Our professionals can efficiently diagnose your AC problem. They can also offer advice on when to replace your air conditioner.

Tom Riggs

Tom Riggs is the Division Manager for Mechanical Services, overseeing sales and operations for HVAC, Plumbing, Electrical, Appliance Repair and Water Quality for all ABC Austin branches. He joined ABC in 2014. Before ABC, he was an HVAC Service Technician, HVAC Comfort Advisor/Sales and Operations Manager. Tom attended Universal Technical Institute. He's an avid outdoorsman and enjoys country living with his wife and two sons.

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