When and How to Change Your Furnace Filter

December 01, 2015

Maintaining your furnace can go a long way in the period in between furnace service appointments. One of the easiest, and essential, ways to maintain your furnace lies in switching out your furnace filter. Having a dirty air filter can contribute to a number of unfavorable problems for your heating and cooling system, its efficiency, and ultimately, how much your energy costs are every month.

So what goes in to deciding when you should switch out your furnace filter?

  • Type of filter: the two most common filter sizes are 1 inch and 3 inch filters. 1 inch filters typically need to be switched out every month and 3 inch filters need to be replaced every three months, based on the recommendations of the filter company.
  • Home habits: if you have pets in your home, it may make sense to change your filter more often because of pet dander. If someone in your family deals with allergies or asthma, consider changing your home’s air filter more frequently to help with their symptoms.

Now you’re likely wondering how to swap out your furnace filter. Inevitably this will vary depending on what furnace you have, but normally: 

  • Open or remove the air filter panel near the bottom of your furnace to uncover an open compartment.
  • On the top of that open compartment is where your furnace filter is resting on two metal supports.
  • There will be a bit of space to move your filter back and forth that allows you to pull down one end of the filter and pull it out of the compartment.
  • When adding the new filter, inspect the perimeter of the filter for an arrow that indicates the air flow direction, to ensure you’re installing the filter in the right direction. In most cases, the arrow should point at the main part (or top) of the furnace. 
At Service Experts Heating & Air Conditioning, we’ll replace standard one-inch furnace filters as part of our regular furnace service Precision Tune-up or PLUS Maintenance Agreement service. Give us a call today at or set up an appointment with us online.