How to Check Your Air Conditioner Before Calling for Service

If your air conditioner is not working or not working well, there are a couple things you should check before calling for service. While your HVAC technician is always happy to help, you can save yourself a service charge by checking to make sure your air conditioner problem is not easy to fix before bringing the HVAC technician to your doorstep.

Top 6 Air Conditioner Problems to Check Before Calling for Service

  1. Check that the thermostat is on and working. You might need to replace the batteries.
  2. Check that the thermostat is set to “cool” and not heat.
  3. Check that the thermostat is set to a temperature lower than the current room temperature. These three steps might seem basic, but they are the first things your service technician will check for. It is sort of like when you call for computer tech support, and they ask if the computer is plugged in and turned on.
  4. Check the air conditioner filter. When did you last change the air conditioner filter? If you cannot recall, look at the air filter and see if it is dirty. Change the air filter and wait a couple hours to see if the air conditioner starts working properly again. Air conditioners simply do not work as efficiently with a dirty air filter. Change the air filter once a month to avoid problems.
  5. Window unit? Check the thermostat sensor; it might be bent out of shape. If so, carefully put it back into position.
  6. Check for a blocked drain. Did you know that air conditioners take moisture out of the air? That moisture needs to go somewhere. If your air conditioner’s drain is blocked, it will keep your air conditioner from working properly. Clear out the drain and see if that solves your problem.


Air conditioners are like plumbing and electrical systems: you only think about them when they are not working properly. Take the time to understand the basics of your home’s HVAC system and create a comprehensive maintenance calendar so that you can keep small problems from becoming big replacement or repair bills. Before calling for service, review the six steps above and see if you can solve your air conditioning problem yourself. If you cannot, give us a call and an experienced HVAC technician will be there to get your home cool and comfortable again.

American Comfort One Hour Heating and Air Conditioning provide HVAC services for the cities of Elk Grove Village, Roselle, Park Ridge, Schaumburg, Chicago, and the following cities in Illinois.