When and How to Change Your Furnace Filter

December 01, 2015

Caring for your furnace can help more than you’d think in the months in between furnace service appointments. One of the most basic, and critical, ways to maintain your furnace is in changing your furnace filter. Having a clogged air filter could contribute to a host of adverse problems for your heating and cooling system, its efficiency, and ultimately, how much you’re spending on your energy bills every month.

So what goes in to determining 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 normally need to be switched out every month and 3 inch filters need to be replaced every three months, dependent on the recommendations of the filter manufacturer.
  • Home habits: if you have pets in your home, it may make sense to replace your filter more often because of pet dander. If a family member has allergies or asthma, think about switching out your home’s air filter more regularly to help ease their symptoms.

Now you’re possibly wondering how to change your furnace filter. Obviously this will vary depending on what furnace you have, but usually: 

  • Open or pull off the air filter panel near the bottom of your furnace to uncover an open compartment.
  • On the top of that open compartment is where you’ll see your furnace filter resting on two metal lips.
  • There will be a little space to move your filter back and forth that allows you to remove one end of the filter and take 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 make sure you’re installing the filter in the right direction. In nearly all cases, the arrow should point at the main part (or top) of the furnace. 
At BW/Cook 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 schedule an appointment with us online.