AC Maintenance Checklist

If you are fortunate enough to have forced air AC, you will want to ensure that you are ready when the temperatures rise! Every spring, you should run through the following list of maintenance items to ensure your AC system is working when you need it, and to prolong its life. It is also a good idea to have an annual or every-other-year maintenance inspection by an HVAC professional.

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Filters - These are the number one maintenance item, and the leading cause of inefficient or ineffective AC systems. The exact replacement frequency will depend on your lifestyle, but you should use these industry standards as a guide and go from there.

If your system uses a single-ply 1″ filter, it should be checked once per month.

For a pleated 1″ filter that has more surface area, it should be checked every three months.

Check 4-inch filters every six months and 5-inch filters every 12 months.

Filters need changing if the filter is visibly dirty, the AC cycles on more frequently than usual, your home has become dustier, or there are unusual smells.  

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Compressor or Condenser Unit - This is the outdoor unit. To help dissipate the heat that gets removed from the home, a big fan pulls outdoor air over the condensing coils and to work properly it needs plenty of airflow. It should not be obstructed by plants, weeds, garden debris or decorative enclosures. Because the fans suck in air on all of the open sides they need to be cleaned from time to time. Inspect all vented sides of your outdoor unit and clean the vents and coils off as needed. Feel free to use a garden hose to help.

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Condensate drain - An air conditioner’s two jobs are to remove heat and remove moisture from the air. To remove moisture, condensation occurs at the evaporator coil located above the furnace and blower. If the condensate line from the evaporator gets clogged it will damage the furnace, and possibly parts of the home. To make sure there aren’t any leaks, remove the blower door to your furnace and look inside that compartment for moisture. Also, find the termination of your condensate drain or condensate pump and visually check that water is dripping out during use. In the event of a leak or a clog, call in an HVAC professional.

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Cool air temperature- Use a thermometer to verify the air conditioner is actually cooling. Use a meat thermometer or an infrared thermometer to check at the filter (input air) and at a vent near the unit (output).The difference in temperature between the air going in and the air coming out should typically be approximately 14 – 20 degrees. If it’s not in or close to that range, it’s probably not cooling properly and it’s time to call in an HVAC professional.