Lee's Air
Blog Hero

Step-by-Step Guide to Replacing Furnace Filters

Book a Service
40 years of service

Many types of HVAC units, from central air conditioners to furnaces, have air filters. These filters are designed to collect all kinds of airborne particles — including dust, pollen, and pet dander — before they have a chance to enter your home.

It’s important to replace your furnace’s air filter regularly to prevent any harmful pollutants from contaminating your air. As a general rule of thumb, it’s a good idea to replace the filter once every 90 days. However, you may want to replace it on a more frequent basis if you have pets or are prone to allergies.

Are you unsure of how to replace furnace filters? There’s no reason to panic! Although this maintenance task might seem complicated, it’s actually a simple and quick process.

Let’s go over an easy step-by-step guide to replacing furnace filters.

Why Do Furnace Filters Get So Dirty?

Your furnace’s air filter can become dirty for several reasons, such as an accumulation of pet hair, the filter’s size, or the presence of excessive dust in your home. When your filter becomes clogged with debris, it can significantly limit the airflow coming and going from the furnace. Unfortunately, insufficient airflow will negatively impact your heating system’s energy efficiency, which can lead to higher energy bills.

As you can see, it’s incredibly important to replace the furnace filter regularly. When you change the filter on a routine basis, you can maintain a high-efficiency HVAC unit. As a result, you can improve your home’s comfort while preventing a premature furnace replacement in Fresno, CA.

Some heating systems use reusable filters. If this is the case for you, all you have to do is clean the filter. If you have a disposable filter, keep reading to see how to change it.

Step 1: Shut Off the Furnace

It’s time to get started with our step-by-step guide to replacing furnace filters! The first thing you’ll want to do is shut off your HVAC system. You should always avoid changing furnace filters while running the heating system, as various types of debris can enter the furnace — and you certainly don’t want that to happen.

How to Shut Off a Furnace

Before diving into how to change a furnace filter, it’s crucial to understand how to safely shut off your furnace. First, locate the switch or dial on or near the furnace. Turn this to the “off” position and wait for the blower fan to completely stop. This might take a few minutes, but it’s a good idea to ensure the system is entirely inactive before proceeding.

How Do You Know If Your Furnace Power Is Off?

After switching off the furnace, you should check if the blower fan inside the air handler has stopped spinning. If it’s still running, wait a few moments for it to stop completely. When the furnace has been shut off properly, you’ll also notice that there is no longer any air blowing out of the vents. Remember, safety comes first!

Step 2: Locate Your Furnace Filter

Now that your furnace has been safely turned off, it’s time to hunt down the location of the air filter. The filter is usually inside the heating system itself, so the first place you should look is the air handler. However, there could be a second filter located within the return air register, so don’t forget to check there as well.

As you can see, there is no one-size-fits-all process when it comes to learning how to replace furnace filters. Some furnaces only have one filter, while others have two. Always be thorough and make sure you’re replacing each filter!

How to Locate Your Furnace’s Air Handler

The air handler is the component of your HVAC system where the filter is located. In most systems, the air handler is near the furnace, often in a basement, attic, or utility closet. Look for a slot with a removable cover; as we mentioned above, this is likely where the filter is housed.

How to Locate Your Return Air Register

The return air register is where your HVAC system pulls in air to be heated or cooled. Here’s how to locate it:

  • Look for large grilles in your home, often located on the ceiling or high on the wall.
  • The grille should have a latch or screws that can be undone to access the filter.

Step 3: Take Out the Old Filter

Once you’ve removed the access panel, you’ll need to remove the existing filter. While extracting the filter, keep an eye on the arrows that should be drawn on the sides of the filter. These arrows point in the direction the air flows, and you’ll want to install the new filter with the arrows pointing in the same direction.

Step 4: Select a Replacement Filter

Our step-by-step guide to replacing furnace filters wouldn’t be complete without this important step. Now that you’ve removed the dirty filter, you’ll want to purchase a replacement that is identical to it. There are many filter sizes and materials on the market, so you’ll want to make sure you choose the correct size and type for your specific needs. You can typically purchase replacement filters in hardware stores or online, so they aren’t hard to find.

Furnace Filter Replacement Options

When learning how to change a furnace filter, it’s also helpful to know that you have many filter replacement options to choose from:

  • Disposable Pleated Filters: Made from polyester or cotton paper sheets, these filters are capable of trapping small particles such as mites and spores. They are reasonably priced and widely available.
  • Disposable Fiberglass Filters: These are the most affordable option. While they are good at capturing large particles, they struggle with smaller ones.
  • Permanent Electrostatic Filters: These filters have self-charging cotton fibers that attract particles. They are washable and reusable.
  • High-Efficiency Pleated Filters: These filters are constructed from four to five-inch pleated synthetic cotton and are held within a rigid frame. They offer the best filtration but can be more expensive.

Step 5: Install the Replacement

We’re almost done! The final step is to install the new filter. This process is pretty straightforward; just remember to point the arrows in the direction of the airflow. Once you’ve successfully set up the replacement filter, simply close the access panel. You can now turn your furnace on and crank the thermostat back up.

And there you have it; we’ve now finished our step-by-step guide to replacing furnace filters! Hopefully, you feel a little better about completing this easy maintenance task on your own. All homeowners should know how to replace furnace filters, as this quick and simple process can end up impacting your heating system’s performance in more ways than one.

Why Is Changing Furnace Filters Important?

Although it’s vital to learn how to change a furnace filter, it’s equally important to understand why this simple maintenance task is so necessary. Changing furnace filters is crucial for maintaining good indoor air quality. Furnace filters are designed to trap dust, dirt, and other airborne particles before they circulate throughout your home. A dirty filter can inhibit airflow, making your HVAC system work harder than necessary, which can lead to increased energy costs and potential damage to the air handler.

In addition, a dirty filter can negatively affect the air quality in your home. By not replacing the filter, dust and dirt can accumulate over time, potentially causing health issues for those living in the house. Therefore, it’s important to check your filter monthly and replace it when needed.

Regular furnace maintenance, including filter replacements, can extend the life of your system and improve your home’s air quality. If you’re not comfortable doing this yourself or if you need a new furnace installed, consider professional furnace installation in Fresno, CA.

How Often Should You Be Changing Furnace Filters?

Now that you know how to change a furnace filter, it’s time to learn how often you should be performing this task. The frequency of changing furnace filters varies depending on the type of furnace filter you have and the air quality in your home. However, a general rule of thumb is to replace the filter once a month, especially during peak usage seasons.

If you have a disposable fiberglass filter, you should replace it approximately every 30 days. Pleated filters, however, can last up to 90 days. High-efficiency particulate air (HEPA) filters can last up to a year, but it’s still a good idea to check your filter monthly.

Schedule Heating Services With Our Professional Team!

As you can see, learning how to replace furnace filters isn’t as complicated as it might seem. If you need to schedule a professional furnace repair in Fresno, CA, turn to Lee’s Air, Plumbing & Heating! Our experts are proud to provide high-quality services for a wide range of heating and cooling systems, including furnaces.

Replacing the air filter is a critical part of maintaining your furnace. However, there may come a time when replacing your furnace is the only way to drastically improve your comfort and energy savings. Don’t wait to get in touch with the experts at Lee’s Air, Plumbing & Heating. Contact us today to schedule an appointment!

Thomas Howard

Written by Thomas Howard

Back to the Blog
instagram facebook facebook2 pinterest twitter google-plus google linkedin2 yelp youtube phone location calendar share2 link star-full star star-half chevron-right chevron-left chevron-down chevron-up envelope fax