Maintaining a Central Air System

Written by Lee Wyatt (last updated June 4, 2021)

During the heat of the summer, a working central air system can make life much more enjoyable. Due to this, it is extremely easy to tell when such a system begins to go on the fritz. Properly maintaining a central air system can go a long way to help prevent any unwanted difficulties from arising. While exceptionally easy, maintaining a central air system will also help protect the valuable piece of equipment that is also an investment.


  • Screwdrivers
  • Trash bags
  • Blower
  • Fin comb
  • 4-foot level
  • Open-end wrench
  • Allen wrench set
  • Electric machine oil, or all-purpose oil
  • Wood shims
  • Replacement fan (if necessary)
  • Rags
  • Gloves


  1. Check for noisy operation. One of the easiest ways to begin maintaining a central air system is to simply listen. Periodically go outside and listen to your fan, and see if it seems to be operating too noisily. The most common cause for a noisy air conditioner fan is that one of the blades somehow became bent. When a fan blade gets bent, it throws the balance of the unit out of whack, and causes the motor to work much harder than it normally would need to.
  2. Clear intake fins and coil. Make sure that the area around the intake fins and coil are free of any dirt and debris. This area of your air conditioner will often attract such messes, and make it much more difficult for the unit to work properly. Use a brush, and a garden hose to remove this mess.
  3. Shut off power. Before opening your air conditioner to do any interior maintenance, make sure that you shut off the power. The simplest way to do this to simply unplug the unit, but you can also disconnect the power at the junction box by throwing the breaker. Be sure that you leave a note saying not to turn the power back on, to ensure that no one accidentally does that.
  4. Remove fan assembly. In order to repair a bent fan blade, or even to inspect the interior of the air conditioner, you will need to remove the fan assembly. Often times, this can be done by loosening the bolts that are found around the edge of the fan assembly, and setting them aside. Remember where you put them so you don't loose them. Once the assembly has been removed, clean out any dirt and debris that may have gotten inside the unit, as well as repairing any bent fan blades. It is always best to take a fan blade into the shop to have it fixed properly.
  5. Check fins. With the fan assembly removed, take a look at the fins to ensure that they are not bent or out of shape. These fins often look like a bunch of black, metal paper stacked vertically. Clean these fins, and straighten any bent ones at the same time, by using a fin comb.
  6. Lubricate the fan motor. Take a look at fan motor by removing the blades from the assembly. Unloosen the setscrew that is holding the fan in place, and set them both aside. Use either multipurpose oil or machine oil that has been formulated for electric motors, and lubricate all the moving parts. Often there are oil ports that you can use to apply the oil to areas of the air conditioner that you may not normally be able to reach.
  7. Reassemble, and ensure unit is level. Reassemble everything, and then check to ensure that it is level. Use a 4-foot level, set on top of the unit, to make sure that everything is level. Make sure that you quarter the unit when checking it to see that it is actually level in the cardinal directions. Use either shims, or adjust the feet of the unit to ensure that everything is level again.

Author Bio

Lee Wyatt

Contributor of numerous Tips.Net articles, Lee Wyatt is quickly becoming a regular "Jack of all trades." He is currently an independent contractor specializing in writing and editing. Contact him today for all of your writing and editing needs! Click here to contact. ...


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