When and How to Change Your Furnace Filter

December 01, 2015

Caring for your furnace can go a long way in the months in between furnace service appointments. One of the easiest, and essential, ways to care for your furnace lies in changing your furnace filter. Having a clogged air filter could contribute to a variety of negative problems 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 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 should be swapped out every three months, dependent on the recommendations of the filter maker.
  • Home habits: if you have pets in your home, it might make sense to change your filter more often because of pet dander. If a family member suffers from allergies or asthma, consider switching out your home’s air filter more regularly to help ease their symptoms.

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

  • Open or take off the air filter panel close to the bottom of your furnace to reveal 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 pull 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 indicates the air flow direction, to ensure you’re installing the filter in the correct direction. In most cases, the arrow should point towards the main part (or top) of the furnace. 
At 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 arrange an appointment with us online.