How to Change a Furnace Filter
I pulled the old filter out and nearly threw it away before I saw the arrow. Turns out the thirty seconds before the swap matter more than the swap itself.
Author
Chris D.
Heating & Cooling Windows & DoorsChris D. writes the Heating & Cooling and Windows & Doors articles for Attic to Porch. Every page lists its sources and the date it was last updated.
How Often to Change Furnace Filter
The box says ninety days, and I believed it for years. Then one winter my furnace started sounding like it was straining, and I finally pulled the filter out to look at it.