How Often Should You Change Your Furnace Filters?

Failure to regularly change your furnace filters will cause your furnace to fail prematurely. Dirty air filters are the #1 cause of furnace breakdowns. A dirty air filter will create drag, which stresses the blower motor, causing it to fail earlier than it normally would. Dirty air filters will also reduce the amount of air flowing through the furnace, which will cause a buildup of heat. This excessive heat will trip safety switches and cause the heat exchanger to fail prematurely.

The general rules for filter changes are as follows:

  • 1” filters changed monthly
  • 2”-3” changed every other month
  • 4”-5” changed every 6 months
  • Electronic air cleaner: Clean following the manufacturer’s recommendations

You will want to change your filter more frequently if you have shedding pets in the home, smoking in the house, home improvement projects which create dust, and an active household (lots of in and out). As you get into a pattern of replacing your filters, you will soon learn how frequent your changes need to be.