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Furnace air filter — photo the size stamp before you discard it

Furnace filter

Before you throw out a dirty furnace air filter, photograph the size stamp so furnace filter size and MERV reorders match — one beat that stops wrong-box buys.

photo furnace filter size stamp before discard — related household tip photo
Photo: Donar Reiskoffer / Wikimedia Commons (CC BY 3.0)

Pull the dirty furnace air filter and photograph the printed furnace filter size (and MERV if shown) before the trash run. That photo beats guessing from memory when the next box must match the slot.

Photograph the furnace air filter size stamp before discard

  1. Slide the dirty filter out and wipe enough dust from the cardboard frame edge to read the stamped size line clearly.
  2. Photograph the full size string (for example 16x25x1) plus any MERV mark; keep it in a home HVAC phone album.
  3. Match the next furnace air filter order to that photo — depth mistakes are as common as length/width mix-ups.
  4. Only then discard the old pad and seat the new one with the arrow toward the blower.

Honest stop: if the stamp is unreadable and the slot has no label, measure the opening carefully or bring the old frame to the store — do not force a thicker MERV pad into a thin slot.

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