When and How to Change Your Furnace Filter

December 01, 2015

Taking care of your furnace can help quite a bit in the time in between furnace service appointments. One of the easiest, and critical, ways to care for your furnace is in changing your furnace filter. Having a clogged air filter may contribute to a number of unfavorable concerns for your heating and cooling system, its efficiency, and ultimately, how much your energy expenses are month after 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 switched out every month and 3 inch filters need to be replaced every three months, based on the recommendations of the filter maker.
  • Home habits: if you have pets in your home, it might make sense to switch out your filter more often as a result of pet dander. If someone in your family suffers from allergies or asthma, consider replacing your home’s air filter more regularly to help potentially decrease their symptoms.

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

  • Open or remove the air filter panel near the bottom of your furnace to expose an open compartment.
  • On the top of that open compartment is where your furnace filter is resting on two metal supports.
  • There will be a small amount of space to move your filter back and forth that allows you to remove one end of the filter and pull it out of the compartment.
  • When adding the new filter, look at the perimeter of the filter for an arrow that indicates the air flow direction, to ensure you’re installing the filter in the proper direction. In the majority of cases, the arrow should point at the main part (or top) of the furnace. 
At Midway Services, 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 arrange an appointment with us online.