When and How to Change Your Furnace Filter

December 01, 2015

Taking care of your furnace can go a long way in the period in between furnace service appointments. One of the easiest, and essential, ways to care for your furnace is in replacing your furnace filter. Having a clogged air filter could contribute to a host of adverse concerns for your heating and cooling system, its efficiency, and ultimately, how much your energy expenses are every month.

So what goes in to deciding 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 normally need to be switched out every month and 3 inch filters ought to be changed 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 change your filter more often as a result of pet dander. If you have someone in the house that deals with allergies or asthma, think about changing your home’s air filter more regularly to help with their symptoms.

Now you’re probably 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 close to 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 supports.
  • There will be a little space to move your filter back and forth that allows you to remove one end of the filter and take it out of the compartment.
  • When putting in the new filter, check 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 most cases, the arrow should point towards the main part (or top) of the furnace. 
At Stevenson 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 set up an appointment with us online.