April 18, 2023

Where is My Furnace Air Filter Located?

where is my furnace air filter located

Where is My Furnace Air Filter Located?

The furnace air filter is essential to any heating and cooling system. It ensures that the air going through your furnace is clean and free of harmful particles, allowing for a more efficient and healthy environment in your home. The air filter in your furnace helps maintain good indoor air quality, prevents dust and other pollutants from being released into your home, and helps prolong your furnace’s life.

However, it’s not enough to just install an air filter and forget about it. Changing the filter regularly is vital to ensure optimal furnace performance and indoor air quality. A clogged or dirty air filter can block airflow and reduce your furnace’s efficiency. It can lead to higher energy bills and premature wear and tear on your furnace.

In addition, a dirty air filter can circulate dust, pollen, and other particles throughout your home, leading to poor indoor air quality and even health problems. That is why changing your furnace air filter every three months, at least, or more often if you have pets or allergies, is essential.

Common Locations of Furnace Air Filters

The location of your furnace air filter may vary depending on the type of furnace you have and how it is installed, but there are generally two common locations that we will dive into below:

Behind the Return Air Grille

The return air grille is the vent that intakes and exhales air to and from the furnace. The air filter is commonly placed right behind the return air grille. To access your furnace air filter in this location, you must remove the grille, usually held in place with clips or screws.

To remove the grille, first, locate the fasteners holding the grille in place and then gently unscrew or release them. After removing the grille, you should see the air filter covering the opening or duct. You can now slide the old, dirty air filter out of its slot and replace it with a clean one.

Inside the Furnace Cabinet

If you don’t see a return air grille in your home, your furnace air filter may be inside the cabinet. To access the air filter in this location, you must turn off your furnace and open the cabinet door. Furnace filters in this location can be a little more complicated to change as there may be some moving parts or connections to work around.

Once you locate the air filter inside the furnace cabinet, check to see if it’s dirty and ready for changing by holding it up to the light. If it looks dirty, remove the existing filter, slide the new one in, and replace any housing cover that may have been present. Observe the arrows on the filter to ensure you have the correct airflow direction.

Tips for Changing Your Furnace Air Filter

Now that we have covered the common locations of furnace air filters let’s discuss some tips for changing the air filter correctly. Follow these tips to ensure you change your air filter safely and with the correct size and type.

Turn Off the Furnace

The first step in changing your furnace air filter is to turn off the furnace. It is critical because it helps prevent harmful particles, dust or debris from being released into your home while changing the air filter. Ensure you turn off the furnace by following the instructions outlined in your furnace’s owner manual to avoid any accidents or malfunctions in the furnace’s functioning.

Take Note of the Air Filter Size and Type

Before removing the old, dirty air filter from your furnace, check the size and type of filter you need. Furnace air filters come in different sizes and types.

Having the right filter size is crucial because an incorrectly sized filter may not fit correctly in your furnace, which can compromise system performance or result in harmful air passing through the filter. The filter type is also crucial, as some filters have different efficiencies, indicating how well they can capture dust or other particles.

Consult your furnace model specifications or check the previous filter to get this information. The size is usually written in inches and can either be air filter thickness and filter length or air filter width and filter length. Note down the dimensions of the filter and check these dimensions against the new filter to ensure you have the correct one.

Insert the New Air Filter in the Correct Direction

Once you have turned off the furnace and removed the old air filter, it’s time to insert the new one. When inserting the new air filter, ensure you put it in the correct direction. Most furnace air filters will have arrows indicating the direction of airflow. The arrows should be facing toward the blower motor or in the direction specified in your furnace’s owner manual.

Push the filter into the filter slot, ensuring a secure fit. If the filter is not fitting, it may not be the correct size for your furnace. Check to make sure you have the correct filter size, and try again.

Dispose of the Old Air Filter Properly

After inserting the new air filter in the correct direction, it’s time to dispose of the old air filter properly. Do not attempt to reuse a dirty air filter, as this could be detrimental to your furnace’s performance and the air quality in your home.

It’s essential to correctly dispose of the old air filter by placing it in a sealed plastic bag before placing it in the trash bin. Disposing of the air filter this way ensures that any particles or pollutants trapped by the filter don’t escape. You can also drop the dirty filters off at local waste management facilities or contact the local authorities for more information on how to dispose of them properly.


In conclusion, changing your furnace air filter regularly is essential as it plays a critical role in ensuring clean and healthy air circulation in your home. Furnace air filters are usually located near where the return duct connects with the furnace, accessed through large metal doors or a removable panel.

To change your furnace air filter correctly, turn off the furnace, take note of the air filter size and type, insert the new air filter in the correct direction, and dispose of the old air filters properly. These steps help ensure your furnace performs optimally and keeps pollutants out of your home’s indoor environment.