When and How to Change Your Furnace Filter

December 01, 2015

Maintaining your furnace can go a long way in the time in between furnace service appointments. One of the simplest, and essential, ways to maintain your furnace lies in changing your furnace filter. Having a clogged air filter could contribute to a number of negative issues for your heating and cooling system, its efficiency, and ultimately, how much your energy costs are each month.

So what goes in to determining when you should replace 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 replaced every month and 3 inch filters need to be changed every three months, dependent on the recommendations of the filter company.
  • Home habits: if you have pets in your home, it could make sense to switch out your filter more often because of pet dander. If someone in your family deals with allergies or asthma, think about switching out your home’s air filter more often to help ease their symptoms.

Now you’re likely 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 expose an open compartment.
  • On the top of that open compartment is where you’ll see your furnace filter resting on two metal brackets.
  • There will be a small amount 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 shows you the air flow direction, to make sure you’re installing the filter in the correct direction. In the majority of cases, the arrow should point towards the main part (or top) of the furnace. 
At McKinley Heating Service Experts, we’ll swap out 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.