Blog Post: Why Is My AC Not Cooling My Home? Common Issues and Fixes

Chattanooga summers are no joke, with humidity and heat making a working air conditioner essential for comfort. If your AC isn’t cooling your home, you’re probably feeling the frustration—especially in neighborhoods like Hixson or East Brainerd, where sticky days are common. As a local Chattanooga HVAC company, we’ve helped countless homeowners tackle this issue. Here’s a look at the most common reasons your AC isn’t keeping up and how to fix it, so you can stay cool all summer long.

1. Dirty or Clogged Air Filters

A dirty air filter is one of the top reasons your AC struggles to cool. In Chattanooga, where pollen from Lookout Mountain and nearby trees blankets the air, filters can clog quickly, choking airflow and forcing your system to work harder. This not only reduces cooling but can also spike your energy bills.

The Fix: Check your filter monthly and swap it out every 1-3 months. Homes in areas like Signal Mountain, with heavy tree cover, might need high-efficiency filters to handle extra pollen. A quick filter change can make a big difference, but if the problem persists, a professional tune-up can ensure your system is running smoothly.

2. Low Refrigerant Levels

Your AC relies on refrigerant to pull heat from your home. If levels are low—often due to a leak—your system can’t cool effectively, leaving your Chattanooga home feeling muggy. This is a common issue in older homes around St. Elmo, where aging systems are more prone to wear.

The Fix: Don’t try to handle refrigerant yourself—it’s a job for a licensed technician. They’ll find and fix any leaks, then recharge the system to get it cooling again. Ignoring low refrigerant can damage your compressor, leading to expensive repairs, so call a Scenic Air as soon as you notice weak cooling.

3. Thermostat Problems

If your thermostat isn’t working right, your AC might not kick on at all. Older thermostats, common in historic North Chattanooga homes, can misread temperatures or fail to communicate with your unit. Even a simple setting error can leave you sweating.

The Fix: Double-check that your thermostat is set to “cool” and the temperature is below the room’s current reading. Replace batteries if it’s battery-powered, or consider upgrading to a smart thermostat for better control and energy savings. Smart thermostats are gaining popularity in Chattanooga for their ability to cut cooling costs during our long summers.

4. Blocked or Leaky Ductwork

Leaky or clogged ducts can steal your AC’s cooling power, leaving some rooms warmer than others. In Chattanooga, where humidity near the Tennessee River can creep into homes, dust and debris often build up in ducts, especially in older properties.

The Fix: Take a look at any visible ductwork for obvious damage or blockages. For a thorough solution, contact Scenic Air to seal and repair your ducts, boosting airflow and efficiency.

5. Frozen Evaporator Coils

Frozen evaporator coils can’t absorb heat, leaving your home warm and sticky. This often happens due to low refrigerant, restricted airflow, or high humidity—a frequent issue in Chattanooga’s climate.

The Fix: Turn off your AC to let the coils thaw, and check for simple issues like a dirty filter. For deeper problems, like leaks or insulation issues, a professional can diagnose and fix the root cause. If you spot frost on your unit, don’t wait—reach out for fast AC repair to avoid further damage.

6. Outdoor Unit Issues

Your outdoor condenser unit needs to release heat to cool your home, but debris like leaves or dirt can block it. In Chattanooga’s wooded areas or after summer storms, units often get clogged, reducing efficiency.

The Fix: Clear away leaves, grass, or debris around the unit, keeping a 2-foot radius free. A professional can clean the coils and check for electrical or fan issues. Regular maintenance is key to keeping your unit in top shape, especially after heavy rain or wind.

7. Aging or Undersized AC Unit

If your AC is over 10-15 years old or too small for your home, it may not handle Chattanooga’s intense summer heat. Older systems in historic districts or undersized units in growing neighborhoods like Ooltewah often struggle to keep up.

The Fix: A Chattanooga HVAC technician can assess whether your unit needs replacing or if a larger system would better suit your home. Modern, energy-efficient ACs can save you money and keep you comfortable through Tennessee’s hottest months.

When to Call a Chattanooga HVAC Expert

Some fixes, like swapping out a filter, are easy enough for homeowners, but most AC issues need a professional touch to avoid bigger problems. If your home still feels warm after basic troubleshooting, it’s time to call a local expert. Our team serves all of Chattanooga, from downtown to East Ridge, with fast, reliable AC repair to restore your comfort.

Stay Cool with Scenic Air!