When and How to Change Your Furnace Filter

December 01, 2015

Caring for your furnace can help quite a bit in the months in between furnace service appointments. One of the easiest, and essential, ways to take care of your furnace lies in replacing your furnace filter. Having a clogged air filter may contribute to a variety of negative problems for your heating and cooling system, its efficiency, and ultimately, how much your energy expenses are 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 usually need to be replaced every month and 3 inch filters should be changed every three months, depending on the recommendations of the filter manufacturer.
  • Home habits: if you have pets in your home, it might make sense to replace your filter more often due to pet dander. If you have someone in the house that suffers from allergies or asthma, contemplate switching out your home’s air filter more frequently to help ease their symptoms.

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

  • Open or pull off the air filter panel around the bottom of your furnace to reveal an open compartment.
  • On the top of that open compartment is where you’ll see your furnace filter resting on two metal supports.
  • There will be a little space to move your filter back and forth that allows you to pull down one end of the filter and take it out of the compartment.
  • When adding the new filter, check the perimeter of the filter for an arrow that indicates 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 to the main part (or top) of the furnace. 
At Knochelmann Service Experts Heating & Air Conditioning, 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.