Why Your AC Is On But Not Cooling
There’s nothing more frustrating than hearing your air conditioner running, but still feeling warm, sticky air inside your home. If your AC seems to be working but your house isn’t cooling down, you’re not alone—this is a common issue, especially during the first big heat waves of the season.
In many cases, the issue is something simple you can check. Other times, it’s best to call a professional. Here are the most common reasons your AC might be running but not cooling—and how to handle them.
1. Clogged Air Filter
A dirty air filter can restrict airflow and make it difficult for your system to push cool air through your home. It also causes your system to work harder, which can lead to bigger issues down the road.
✅ Quick fix:
Pull out your air filter and check it. If it looks dirty or dusty, swap it out. During warmer months, it’s best to check your filter every 30 to 60 days.
2. Incorrect Thermostat Settings
Before diving into more complex issues, double-check your thermostat. If it’s accidentally set to “Fan” instead of “Cool,” your system might be blowing air—just not cold air.
✅ Quick fix:
Make sure your thermostat is set to “Cool,” and that the temperature setting is lower than your current room temperature. If it runs on batteries, try replacing them too.
3. Blocked or Leaky Ducts
If you’re getting airflow, but it doesn’t feel cold—or some rooms feel cooler than others—your ductwork could be the culprit. Blockages or leaks can prevent cool air from reaching certain parts of your home.
🛠️ What to do:
This one’s best handled by a professional. A technician can inspect your ductwork and make any needed repairs to restore proper airflow.
4. Low Refrigerant Levels
Your system needs refrigerant to pull heat from inside your home. If levels are low, it can’t cool effectively—even if everything else seems to be running just fine.
🛠️ What to do:
Low refrigerant usually means there’s a leak. A certified technician can locate the leak, make the repair, and recharge your system.
5. Dirty Outdoor Unit (Condenser)
Your AC’s outdoor unit is responsible for releasing heat. If it’s covered in dirt, leaves, or debris, it can’t do its job efficiently.
✅ Quick fix:
Turn off power to your unit, then carefully rinse the outside coils with a garden hose (never use a pressure washer). Be gentle and keep the area around the unit clear of debris.
6. Failed Compressor or Capacitor
If your AC is running but not cooling at all, and you’ve ruled out other simple issues, there may be a problem with the compressor or capacitor—both are key components for cooling.
🛠️ What to do:
These are complex electrical parts and should only be handled by a licensed technician.
When to Call in the Pros
If you’ve tried the basics and your AC still isn’t keeping you cool, it’s time to schedule a professional inspection. Our experienced team at Brandywine Heating & Air Conditioning is here to diagnose the issue and get your comfort back on track—quickly and reliably.
📞 Need service fast?
Give us a call or book an appointment online!