← All tips
Comfort
How Often Should I Change My Furnace Filter?
A simple filter schedule for Wisconsin homes and why a clean filter protects your furnace and AC.
A general rule
Thin 1-inch filters: check every month and change at least every 1–3 months. Thicker 4–5 inch media filters: usually every 6–12 months. Homes with pets, allergies, or construction dust need more frequent changes.
Why it matters
The same filter serves your furnace in winter and your AC in summer. A clogged filter makes the blower work harder, can overheat the furnace, and can freeze your AC coil.
Easy way to remember
Pick a date — the first of the month or when you pay a utility bill — and check it then. Write the install date on the filter's edge.