How to Change Your Furnace Filter in 3 Easy Steps

Being a homeowner is exciting, but it does require some DIY maintenance that isn’t always so thrilling — like changing a furnace filter.

If you’re like many homeowners, you may not even know what a furnace filter is, let alone how and when to change it! That's why we've compiled a list of simple instructions on how to change a furnace filter in three easy steps.

Step 1: Determine Which Size Filter You Need

The first thing you need to do is identify which kind of filter you have and need to replace. After you have turned off your furnace, remove the existing filter, which is located just inside the furnace or inside the air return vent.

You should see an arrow on the furnace filter, which will indicate which direction the air flows. Use a sticky note or permanent marker to mark the direction of the air flow on the exterior of the furnace. This way you’ll always know the correct way to install the filter.

Once you’ve removed the filter, make note of its size on the cardboard frame, so you'll know which size to buy.

Related: The Secret to Avoiding Heating and Cooling System Breakdowns: Maintenance

Step 2: Find the Right Replacement

Now that you know what size furnace filter you need, all you have to do is purchase it. You can typically find furnace filters at home stores, hardware stores or online. If you're looking to save on costs, American Home Shield^® offers filters at discounted prices here.

Step 3: Install Your New Filter

When installing your new furnace filter, you’ll see markings that tell you which side of the filter should face the furnace. Slide the filter into place and put the cover back over it. Keep note of the date you changed the filter, so you know when to change it again.

And that’s that! Who knew changing a furnace filter would be so simple?

Related: How to Conduct a DIY HVAC Inspection

Other Frequently-Asked Furnace Filter Questions

Is a furnace filter the same as an air filter?

Yes. The furnace and air conditioner typically share the same air handler. So now that you know how to change a furnace filter, you also know how to change an air conditioner filter.

What if I have a plastic-framed air filter?

If this is the case, you have a reusable filter. There's no need to replace this filter; just clean it periodically by removing it and spraying off the dust with a garden hose. Allow the filter to dry completely before putting it back in the furnace.

How often should I change my furnace filter?

You may think you only need to change your furnace filter once a year, but this can cause your furnace to work too hard, overheat and shut down. A good rule of thumb is to check the filter once a month. Hold your furnace filter up to the light. If you cannot see the light clearly, it is time to replace the filter.

Related: What Is the Difference Between a Furnace and a Boiler?

AHS assumes no responsibility, and specifically disclaims all liability, for your use of any and all information contained herein.