When and How to Change Your Furnace Filter

December 01, 2015

Caring for your furnace can help more than you’d think in the months in between furnace service appointments. One of the simplest, and essential, ways to maintain your furnace is in switching out your furnace filter. Having a clogged air filter could contribute to a number of negative problems for your heating and cooling system, its efficiency, and ultimately, how much you’re spending on your energy bills every month.

So what goes in to deciding when you should change 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 should be swapped out every three months, based on the recommendations of the filter manufacturer.
  • Home habits: if you have pets in your home, it could make sense to replace your filter more often due to pet dander. If you have someone in the house that has allergies or asthma, consider replacing your home’s air filter more regularly to help with their symptoms.

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

  • Open or take 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 will find your furnace filter resting on two metal lips.
  • There will be a small amount of 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 installing the new filter, check the perimeter of the filter for an arrow that specifies the air flow direction, to ensure you’re installing the filter in the right direction. In the majority of cases, the arrow should point to the main part (or top) of the furnace. 
At 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 arrange an appointment with us online.