Changing Your Furnace Filters: Why, When, and How

As a homeowner, it is extremely important to regularly change the furnace filters in your home. Your furnace filters, also called air filters or A/C filters, play a crucial role in your HVAC system and ensure you and everyone in your home are breathing clean and healthy air. If your furnace filter is full of dirt, dust, and other pollutants, it is time for a replacement. Continue reading our blog to learn the importance of changing your furnace filters, how often to replace them, and how to locate and replace them.

Extend Your HVAC’s Lifespan

Regularly changing your furnace filters will help your HVAC system last longer and continue to run efficiently over time. A dirty and clogged filter can cause serious damage to your heating and cooling system. In fact, a dirty filter is a common cause of heating and air conditioning breakdowns. When the air can’t flow through the system due to a clogged filter, it can cause the furnace to overheat and lead to it eventually breaking down. It can also cause your A/C coil to freeze, your HVAC system to start and stop constantly, or your system to stop working altogether. And the last thing you want to do is make costly repairs or purchase a brand-new system.

Improve Air Quality in Your Home

Breathing healthy and clean air is essential to your overall health. Having poor indoor air quality in your home can cause numerous symptoms like sneezing, eye irritation, and other respiratory issues. Changing the furnace filters in your home will prevent allergens and other pollutants from building up in the air inside of your home. If your filters are full and cannot trap any pollutants, then the pollutants have no choice but to flow somewhere else in your home, leading to poor air quality.

Lower Your Electric Bill

A clogged air filter can cause your electricity bill to skyrocket. This is due to the fan motor in your system working twice as hard as it usually does, resulting in an increase in your energy usage. You can save 5 to 15% on your utility cost by changing your furnace filters regularly.

The Pollutants Found in Air Filters

Your furnace filter works extra hard trying to keep your air healthy and flowing efficiently. It keeps the bad and nasty pollutants from entering your respiratory system. Some of the pollutants that are typically found in your air filter are:

• Dust
• Allergens
• Mold spores
• Pet hair

How Often to Change a Furnace Filter

For most standard 1-to-2-inch filters, you should replace them every 2–3 months or whenever they look dirty. A good rule of thumb is to check your furnace filter every month to see if it has significant buildup of pollutants, and to replace it if it does. You can also check your filter’s manufacturer recommendations for how often it should be replaced.

Thicker filters can last longer than standard 1-to-2-inch filters. For example, 3-to-4-inch filters can last 6–9 months before needing replacement, and 5-to-6-inch filters can last 9–12 months. However, you should still check them monthly to make sure.

How often you need to change your furnace filter also depends on how many people are living in your home, if you have pets, if anyone smokes, and other sources of pollutants. If you have shedding pets, for example, you will likely need to change your filter more often than if you did not.

A filter with a higher MERV rating can also help catch more pollutants, such as pet dander. Learn more about MERV ratings in our other blog post.

How to Change a Furnace Filter

Changing your furnace filter is easy if you know what to do! Here’s a step-by-step guide:



1. Turn off your HVAC system using the thermostat or the power cut-off switch.
2. Locate your furnace filter. In most homes, the filter is located in the furnace’s blower compartment. It may also be in a compartment by the air handler, or there may be multiple behind the air return vents in the walls and ceiling.
3. Remove the current filter. You’ll have to remove the door or access panel first. Check the sides of the current and new filters for arrows indicating the direction of airflow through them. Air should flow into the furnace or into the ductwork toward the furnace.
4. Install the new filter. Again, make sure the airflow arrows are pointing the same direction that the air should be flowing.

Contact Hanson’s Plumbing & Heating

At  Hanson’s Plumbing & Heating , we are experts in highly efficient heating and cooling. We believe that home comfort is a top priority, and your comfort and peace of mind is our ultimate goal. If you need a routine maintenance check on your HVAC system or need your air filters replaced, our trusted technicians are here to help. As part of our annual HVAC Maintenance Agreement Program , we can help you locate and change your furnace filter and even perform a full system check for issues.  Contact us  today to sign up or to schedule an appointment!