How to Properly Change a Furnace Filter


Get a breath of fresh air inside your home — it takes just a few minutes to replace your dirty furnace filter.


  • Vacuum cleaner
  • Furnace filter


  1. Locate the furnace filter

    Find the furnace filter:

    • In a furnace, it's usually near the fan.
    • In a fan coil, it's either under the front panel or accessible from one end of the unit.
    • In a return air vent, it's behind the grille.

    Important: If you have a return air grille with a filter back, you don't need a filter in your furnace or fan coil.

  2. Remove the filter


    If the furnace filter is behind a cover, remove the cover. If clasps hold the filter in place, turn the clasps to release the filter.

    Holding the sides — not the filtering material — slide out the furnace filter (in a fan coil, you might have to push it down first). If the filter is marked with a directional arrow, note which way the arrow points.

  3. Clean the area

    Vacuum up dust and debris in the area, to keep dirt from getting into the unit and circulating through the house.

  4. Insert the new furnace filter

    Slip the new furnace filter into position — make sure it's in all the way. If the filter is marked with a directional arrow, verify that the arrow points in the same direction as the arrow on the old furnace filter.