How Often Should You Replace Your Furnace Filter?

You probably don’t think about your furnace very often, let alone the air filter installed in the return vent. However, if you want to lower your heating bills, enjoy cleaner indoor air, and prevent overworking the HVAC equipment, you should replace your furnace filter regularly. Learn when to check the filter and how you know it’s time to change it.

You probably don’t think about your furnace very often, let alone the air filter installed in the return vent. However, if you want to lower your heating bills, enjoy cleaner indoor air, and prevent overworking the HVAC equipment, you should replace your furnace filter regularly. Learn when to check the filter and how you know it’s time to change it.

How Often to Replace the Furnace Filter

The type of filter you have and the conditions in your home determine when you should replace it. Just follow these guidelines:

Replace the filter every 30 to 60 days if:

  • You have a standard 1- to 3-inch filter. These are the most common filters used in residential HVAC systems.
  • You have allergies or asthma. You’ll appreciate the better indoor air quality that comes from having a clean furnace filter, so replace it once a month.
  • You own a pet. Most dogs and cats shed, so even if you don’t have allergies, their fur and dander can clog up ordinary filters fast.
  • You frequently open the windows and doors. This lets pollen, dust, and other outdoor contaminants inside, adding to the layer of filth on your air filter.
  • You or someone you live with smokes. Always smoke outside or plan to change the filter every one to two months.

Replace the filter every 90 days if:

  • You live in a pet-free, smoke-free home and don’t have sensitivities. Most standard filters are rated to last 90 days, so if there are no other air quality concerns, feel free to get the longest lifespan from your filter.

Replace the filter every 6 to 12 months if:

  • You have a more advanced filter. High-efficiency 4- and 5-inch filters last longer.
  • You live alone. Single-occupant homes produce less dust and debris for the filter to trap.
  • You rarely run the furnace or air conditioner. Less air passing through the filter means it stays clean longer.
  • The filter is in a vacation home. You should still check the filter every time you visit, but you can go up to 12 months before changing it.

How to Tell When it’s Time for a Furnace Filter Replacement

In addition to following the timelines above, watch for these signs of a clogged furnace filter:

  • The filter appears dirty when you check it.
  • The furnace runs more frequently than normal.
  • Your home seems dustier than usual.
  • Sensitive family members experience heightened allergy or asthma symptoms.
  • You notice reduced airflow from your supply vents.

If you need help replacing your furnace filter, or you have other questions about maximizing heater performance this winter, reach out to Parley’s PPM Plumbing, Heating & Cooling. We have served Utah residents since 1979, offering unparalleled customer service and quality HVAC maintenance, repairs, and installation. For more about our services, please call 801-850-9446 for Utah County residents or 801-228-0055 if you live in Draper or Sandy. You can also contact us online with any questions you have.