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Furnace air filter — check it sooner in a home with shedding pets

Furnace filter

Dogs or cats that shed can clog a furnace air filter early. Peek at the filter monthly and swap when it looks gray and furry, not just by the calendar.

Illustration of a pleated furnace air filter covered in pet fur beside a friendly dog
Photo: CoraCo Studio™ original (generated)

Pet hair and dander collect on a furnace air filter faster than a calendar reminder expects. A quick look each month tells you when it is really time.

Check a furnace air filter sooner with shedding pets

  1. Turn the system off and slide the filter out.
  2. Hold it up to a light. If you cannot see light through the pleats, or fur coats the surface, swap it.
  3. Install the new filter with the arrow pointing toward the furnace, in the direction of airflow.
  4. Write the date on the frame and look again in a month.

If you see pet fur matted over most of the filter, a monthly look is a better habit than waiting for the next season.

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