Replace Your Furnace Filter: How Often and Why?

A working furnace is the heart of every home. It not only keeps you warm during chilly nights, but a well-maintained furnace will reduce utility costs so you can afford healthier living.

If you want your furnace to work properly and last so long, it’s crucial to replace its filter correctly and frequently. Here are the best practices for replacing a furnace’s filter.

Why You Must Replace Your Furnace Filter

Clean furnace filters keep your ductwork clean of dirt, allergens, viruses, dust buildup and other air pollutants. A filthy furnace filter forces your furnace fan to work harder, leading to extended heating and cooling cycles and higher energy costs. Clogged filters may also help make your HVAC system work harder, leading to reduced efficiency.

According to the EPA, we breathe five times more polluted air in our homes than in the open air. Change your furnace filter regularly so it can do its job of purifying your home’s air.

When to Replace a Furnace Filter

The size is usually listed on the filter. You will also find in the manual of your furnace what size the filter should be since furnaces usually use one size. Filters that are thinner will have to be changed more often.

Follow this schedule to replace your furnace filters:

  • For 1-inch to 2-inch filters, every 1-3 months
  • For 3-inch to 4-inch filters, every 6-9 months
  • For 5-inch to 6-inch filters, every 9-12 months

You should check your filter monthly since some factors unique to your home, family and HVAC system may negate this schedule and require you to replace your filter more frequently.

You should replace a filter more often if:

  • You have young children, pets, or if you or any of your family members have allergies or asthma
  • You open the windows and doors often, building up more dust inside your home
  • Your home is larger. A smaller home may not require as frequent a change of filters.
  • The HVAC system is producing odd smells, especially a burning odor
  • The HVAC runs more often than usual

You might have to replace filters for your HVAC system that should last for 90 days every 30 days if the outside temperature is excessively cold or hot, or if your system runs constantly to keep up.

If you find you’re still running into issues with your furnace, think about changing the furnace filter and seeking the help of an HVAC professional.