Troubleshooting Central Air Conditioners: 3 Common Issues And Solutions

Posted on: 22 December 2014


When the temperature outside begins to rise, you probably look to your air conditioner for relief. But what do you do when your AC unit suddenly stops working? Calling a professional HVAC repairman is one option—but if the problem is mild, you can probably fix it yourself.

Here are three common issues with central air units and simple fixes for each:

1. The Unit Is Not Running At All

If you switch the unit on and nothing happens, it is likely that there are issues with the power. Fortunately, power issues are the easiest to fix.

First, check to ensure that the unit is plugged into the outlet. If it is, head to your electrical fuse box and look to see if the circuit is tripped. If so, reset the switch by flipping it off and then back on.

2. The Unit Is Not Cooling Properly

The unit may seem to work just fine, until hours later when you realize that the room is still warm. If the unit is on and running, it is possible that there are issues with the thermostat or evaporator. It is also possible that the temperature outside is too hot.

However, you can still troubleshoot this issue. Start by turning the temperature on the unit down by 5-degrees. If that does not resolve the issue, double-check that the temperatures outside aren't over 100-degrees—because when it gets that hot, it is hard for the unit to cool the home to the desired temperature.

If your unit still isn't cooling the room properly, look at the evaporator—the coils located above the main duct of the unit. If they are dirty, use a damp cloth to remove any dirt and debris. Once clean, the unit should be able to cool the room much more effectively.

3. The Unit Turns On and Off

Another common issue with central air conditioning units is that they turn on and off repeatedly—all by themselves. Although this can signify a deeper issue, it usually means that the unit needs a good cleaning.

Turn the unit off and wipe down every part of it with a damp cloth. While you are at it, replace—or at the very least, clean—the air filters. Turn the unit back on and see if that helps.

These three issues are the most common in central air conditioning units. If you notice that your AC unit has suddenly stopped working, use these troubleshooting tips to resolve the issue. If your unit still doesn't work after attempting these, call a professional HVAC repairman for help.