When and How to Change Your Furnace Filter

December 01, 2015

Caring for your furnace can go a long way in the time in between furnace service appointments. One of the simplest, and essential, ways to care for your furnace lies in switching out your furnace filter. Having a dirty air filter may contribute to a number of negative concerns for your heating and cooling system, its efficiency, and ultimately, how much your energy expenses are each 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 swapped out every three months, dependent on the recommendations of the filter manufacturer.
  • Home habits: if you have pets in your home, it might make sense to change your filter more often as a result of pet dander. If you have someone in the house that suffers from allergies or asthma, think about switching out your home’s air filter more frequently to help potentially decrease their symptoms.

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

  • Open or take 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 your furnace filter is resting on two metal lips.
  • There will be a little space to move your filter back and forth that allows you to bring down one end of the filter and remove it from the compartment.
  • When putting in the new filter, inspect the perimeter of the filter for an arrow that shows you 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 McElroy 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.