Instructions for a Naturalaire Furnace Filter

Naturalaire is a brand of air filter for home heating and cooling systems. The filter fits inside the blower compartment on the furnace, which is a stainless steel box connected to the ductwork. Naturalaire filters come in a variety of sizes to fit different furnace models, so it's important to check the dimensions of the old filter before installing a new one. Furnace manufacturers typically recommend changing the filter once a month to catch dust particles that would otherwise blow into your home.

Step 1

Shut off power to the furnace.  A breaker switch is typically built into the side of the furnace, or you can cut off the unit at the household circuit breaker.

Step 2

Open the blower compartment on the side of the furnace, using a screwdriver to turn the screw latches that release the vented cover.  On some models the screws may not come out completely.

Instead, twist each screw half a turn counterclockwise to disengage the latches and open the cover. 

Step 3

Pull out the old filter and check the printing around the frame for the dimensions, for example, "12 x 24" If the dimensions are not printed on the old filter, measure the part with a tape measure and write down the length and width in inches to purchase the correct Naturalaire replacement. 

Step 4

Insert the new Naturalaire filter into the compartment with the arrow on the edge of the filter facing inward toward the blower. 

Step 5

Close the cover and turn the screw latches to hold the cover in place. 

Step 6

Restore power to the furnace. 

Things You Will Need

  • Screwdrivers
  • Tape measure

About the Author

James Clark began his career in 1985. He has written about electronics, appliance repair and outdoor topics for a variety of publications and websites. He has more than four years of experience in appliance and electrical repairs. Clark holds a bachelor's degree in political science.