When and How to Change Your Furnace Filter

December 01, 2015

Maintaining your furnace can go a long way in the months in between furnace service appointments. One of the simplest, and crucial, ways to care for your furnace is in changing your furnace filter. Having a clogged air filter can contribute to a number of unfavorable issues for your heating and cooling system, its efficiency, and ultimately, how much your energy costs are month after month.

So what goes in to consideration 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 changed 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 deals with allergies or asthma, contemplate switching out your home’s air filter more regularly to help with their symptoms.

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

  • Open or take off the air filter panel near the bottom of your furnace to reveal an open compartment.
  • On the top of that open compartment is where you will find your furnace filter resting on two metal brackets.
  • There will be a bit of space to move your filter back and forth that allows you to bring down one end of the filter and pull it out of the compartment.
  • When installing the new filter, inspect the perimeter of the filter for an arrow that indicates the air flow direction, to be sure you’re installing the filter in the correct direction. In nearly all cases, the arrow should point to the main part (or top) of the furnace. 
At Coastal Service Experts, 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.