Troubleshooting an AC That Doesn’t Cool

There’s nothing more frustrating than flipping on your air conditioner during a heatwave—only to find warm air blowing out of the vents. If your AC isn’t cooling, don’t sweat it just yet. At Bob’s Air Repair, we’ve seen it all, and many common issues can be identified—and sometimes even resolved—without the need for a service call.

Here’s a guide to help troubleshoot the problem and get your cool air flowing again.

 

1. Check the Thermostat Settings

Start with the basics. Make sure your thermostat is set to “Cool” and that the temperature is set lower than the current room temperature. Sometimes, a simple bump or accidental change in settings can stop your system from cooling.

 

2. Inspect the Air Filter

A clogged or dirty air filter can block airflow, forcing your system to work harder and reducing its cooling efficiency. If your filter looks dusty or hasn’t been changed in over a month, it’s time for a replacement.

 

3. Examine the Circuit Breaker

If your AC isn’t turning on at all, the issue might be electrical. Head to your breaker panel and check for any tripped breakers. Reset them if necessary, but if they trip again, call a professional—this could signal a more serious issue.

 

4. Check the Outdoor Unit

Your AC system has both indoor and outdoor components. If the outdoor unit is covered in debris (leaves, dirt, grass clippings), airflow can be restricted. Gently clear away any buildup and make sure the unit has space to breathe.

Also, listen for any unusual noises—like buzzing or clicking—that might indicate a problem with the fan or compressor.

 

5. Inspect the Refrigerant Lines

Low refrigerant levels or a leak can prevent your system from cooling properly. If you notice ice forming on the refrigerant lines or suspect a leak, it’s time to call in the pros. Handling refrigerant requires EPA-certified technicians.

 

6. Evaluate the Ductwork

Leaks or blockages in your air ducts can prevent cool air from reaching your living spaces. You might notice uneven cooling from room to room or weak airflow from vents. A duct inspection can help identify any hidden issues.