How Do You Remove Bad Smells From a Central Air System?

To purge a central air system of odors caused by mold or mildew, replace the filter, inspect and clean the top of the air conditioner, clean the condensate drain, and evaluate the results. This procedure takes several days and requires a new filter, a wrench, bleach and a scrub brush.

  1. Replace the filter

    Purchase a new filter of the same type and dimensions as the existing one. Remove the filter cover, pull out the old filter, and insert the new filter. Close the filter compartment, and discard the dirty filter.

  2. Inspect and clean the top of the air conditioner

    Open the top of the central air unit. Look for mold or mildew stains on all visible interior areas, and remove them with a scrub brush dipped in bleach.

  3. Clean the drip pan and condensate drain

    Unfasten the condensate drain cover, and pull out the drip pan. Inspect the pan for debris, clean it, and fill it with bleach. Set it aside. Dip a scrub brush in bleach, and scrub the interior of the condensate drain. Pour the bleach out of the pan, set it back in the drain, and close the drain cover.

  4. Evaluate the results

    Evaluate the results for several days. If the unpleasant odor disappears, take no further action. If it remains, seek professional help.