1. United States
  2. Filtrete Home Filtration Products
  3. Home Tips
  4. DIY AC Fixes: Troubleshoot Problems Yourself
  • Troubleshooting Tips for AC Efficiency

    Here’s how to work through AC problems yourself.

    The number one maintenance task for AC efficiency, according to the U.S. Department of Energy: Change air filters regularly.

    • Air conditioner on the fritz? That’s not cool. Before you call an expert, try these tips to get it going—plus a select few to keep it properly maintained, too.

      Uh-oh: What to do when your AC unit is dead.

      No fan, no cooling. Nothing.

      Check the thermostat.
      Double check: Is the AC on and set to cool? Is the set temp several degrees cooler than what your home’s at now?

      Check the power.
      Tripped circuit breakers and blown fuses are common, easy fixes. Just reset or replace. Check power on the indoor and outdoor units to be sure all switches are flipped to “on.”

      Uh-oh: What to do when your AC unit isn’t cooling consistently or well.

      It seems to be running okay, but there’s not a lot of cooling happening.

      Check the registers.
      Inspect every register to make sure it’s clear of furniture, totally open and clean.

      Change the air filter.
      Old furnace filters can’t capture air quality culprits (think: pet dander, candle smoke, allergens) as well as new ones. It’s recommended that you change Filtrete™ air filters at least every three months for optimal performance, but you should replace your filters more often if you’re running the AC 24/7 or if your home has pets or allergy sufferers.

      Check the condensate drain or tray.
      The air handler, which is the unit inside your home, collects water from the air, and may automatically shut your AC off if the tray fills or drain tube gets clogged. Dump the water and replace the tray, and/or clean the tube out with a nice, stiff wire.

      Check the evaporator coil.
      Turn off power to your heating and cooling system at the breaker, remove the access panel and check the evaporator coil for ice or dirt. If you see ice, turn the power back on and run the fan for an hour or two, minimum, to melt it. If it’s dirty, clean it with warm, soapy water and a soft-bristled brush, or a commercial foaming evaporator coil cleaner.

      Clean the outdoor unit (a.k.a. condenser).
      Shut off the power, and clear away any brush and debris within a 2-foot radius. Vacuum the unit’s aluminum grill-like fins and repair any bent ones with an inexpensive condenser fin comb. Then rinse the unit well with a hose sprayed at a 45-degree angle, or use a commercial foaming condenser coil cleaner. Be sure to follow the manufacturer’s directions.

      Keep it going: General AC maintenance tips

      Three things to do on the regular to give your AC unit a long, more efficient life.

      Change that filter.
      The No. 1 maintenance task for AC efficiency, according to the U.S. Department of Energy: Change air filters regularly*.

      Clean it.
      Keep the coils on both the indoor and outdoor units clean, as outlined above. Occasionally pass a stiff wire through the air handler’s drain channels to prevent clogs.

      Call a pro.
      Get an annual pre-season checkup by a licensed HVAC technician to head off problems.


      * U.S. Department of Energy