Rheem Furnace Filter Replacement

Rheem furnaces are top-notch units known for their durability. Although these units are built to last, it’s important to carry out routine maintenance so your heating system stays reliable. If you’re looking for information on how to care for your HVAC system, this Rheem furnace filter replacement guide explains the process clearly so you can maintain your unit with ease.

How Often Should I Change the Furnace Filter?

Time and frequency are an essential part of gas furnace maintenance. Different indoor factors like animals or smoke will change how often you will want to change out the filter. Here are some of the following recommendations:

• Standard use - Change every 90 days
• High use (Allergies/Animals/Smokers) - Change every 30-60 days
• Minimum use - Change at least twice a year

What Size Filter Do I Need for My Rheem Furnace? 

How do you know which size furnace filter? The easiest way to determine the correct size is by checking the size on the current filter’s edge or by checking your owner’s manual. Some of the common Rheem furnace filter sizes you will see are:

• 16 x 20 x 1
• 20 x 20 x 1
• 16 x 25 x 4
• 16 x 25 x 1

Supplies

• Filter (refer to your unit’s manual to determine the appropriate filter)
• Cell Phone/Camera
• Pen or Permanent Marker (optional)
• Calendar (optional)
• Flathead Screwdriver (optional)

How to Change the Filter 

• Step 1. Turn off the thermostat - Switch the thermostat to “off.”
• Step 2. Cut power to the furnace - Use the switch on or near the furnace to power down the unit.
• Step 3. Locate the filter - In most models the filter is located in the same compartment as the blower, but it may also be located in a separate section directly under the blower. If needed, use your unit’s manual to determine the filter’s location.
• Step 4. Open the compartment - If the filter is located near the blower, open the compartment door by turning the screws either by hand or with a flathead screwdriver. If the filter is located in a separate compartment, remove the cover.
• Step 5. Note the old filter’s orientation - Take a photo of the installed filter, paying close attention to how it’s positioned in the unit. Be sure to note the direction in which the arrows are pointing.
• Step 6. Remove the old filter - Pull the old filter out of the unit, being careful so as not to loosen the dust or debris. Once the old filter is out of the unit, discard it.
• Step 7. Unpackage the new filter - Remove the plastic packaging from the new unit. Confirm that it’s the correct size and MERV rating for your furnace.
• Step 8. Write the date of installation on the new filter (optional) - Although this step is optional, writing the installation date on the new filter may make it easier to follow the routine maintenance schedule and replace the filter regularly.
• Step 9. Install the new filter - Slide the new filter into the appropriate space, making sure that the orientation is correct and that the arrows are pointing towards the center of the unit.
• Step 10. Close the compartment - Align the holes at the top of the blower compartment door with the screws on the unit. Attach the door by tightening the screws, either by hand or with a screwdriver. If you put the filter in another compartment, close it securely.
• Step 11. Schedule the next filter replacement - Note the date of filter installation, as well as a date 90 days in the future to change out the filter, in your phone or on a calendar. Setting the date in your phone or on a calendar may be helpful.
• Step 12. Use the furnace normally - Restore power by flipping the main switch and then turning the thermostat to “on.” You can now resume normal operation.

Why Is It Important to Change the Furnace Filter? 

Furnace filters keep dust, debris and other particles from entering the unit, improving its efficiency and preventing damage that may require expensive repairs or even replacing your unit entirely. Filters also improve the general air quality in your home, helping you and your family breathe easily and stay healthy.

Where is the Filter on a Rheem furnace? 

The filter is located in the blower section of the unit, normally on the side of the cavity. However, depending on how your unit was installed, the filter may be located in a separate compartment just under the blower.

What MERV Rating Is Best for a Rheem Furnace Filter? 

Use a filter with a MERV rating of at least 8. However, filters with a MERV rating above 13 may actually force your unit to work harder, so be sure to check your owner’s manual to determine the maximum MERV rating that’s appropriate for your model.

In What Direction Should I Put a Rheem Furnace Filter? 

Install the filter so that the arrows on the frame point towards the center of the unit. 

What If My Unit Has a Washable Filter?

If your gas or oil furnace has a washable filter, follow the same procedures outlined in this guide except for discarding the filter. Instead, blow off large particles with a vacuum and wash off smaller ones with water. Then, dry the filter, put it back into the unit and resume operation.

For more information on using, maintaining and troubleshooting your unit, take a look at the large library of Rheem manuals and diagrams on our site.

Please contact a local authorized service agent who can help with this specific unit and all your heating and cooling needs.