Basic AC Troubleshooting Tips

The best person to diagnose and fix your air conditioner (AC) is a professional AC technician. However, there are a few basic things you can check before calling the technician. At best, you may be able to fix the issue without the technician. At worst, you will rule out the basic issues and help the technician diagnose the fault fast. Below are some of the things to check first.


If your AC is not running at all, the first thing to check is if it is getting power. The AC needs electricity to run the motor, fan, belts, and associated parts. Maybe a temporary malfunction has tripped the breaker, and all you need to get your AC running again is to reset it.


The thermostat is the control point for the AC. A wrong thermostat setting can easily make you think that your AC is malfunctioning. For example, if the thermostat is displaying the wrong date, it might trigger a cooling program for the meant for the middle of the summer even if the summer is just beginning. Therefore, confirm that the thermostat is properly set before moving to other things.

Air Registers

The air registers are the openings through which the ducts deliver air into different parts of the house. Therefore, if an air register is blocked, the affected part of the house won't get the cool air it deserves. Therefore, check if something is blocking the air registers if one part of the house is not as cool as the others. Maybe a renovation or a decoration project has placed something in the register. Or maybe the damper (the mechanism for opening or closing the register) is stuck.


Air filters trap debris in the air before the air gets to the AC for cooling and recirculation. With time, the trapped debris accumulates and blocks the further flow of air through the registers. Thus, you might not have adequate cool air in your house if your filters are dirty. Check your filter replacement program or the filters themselves and replace as necessary to encourage airflow.


A typical central AC has two fans; one outside and one inside the house. The fan inside the house facilitates airflow into the ducts and into different parts of the house. The fan outside the house cools the refrigerant so that it can recirculate inside and pick up more heat. Both fans have motors that drive them.

Damage or malfunction of the fan inside the house will result in no air blowing into the ducts. Damage or malfunction to the fan outside the house will result in warm air blowing through the registers. Check to confirm if either of these fans has malfunctioned if you are experiencing such problems. Contact an air conditioning service for more help.