Filter replacement
How to Replace a 20×25×5 Media Filter
5" media lasts longer than 1" pads but still loads up. Match 20×25×5 exactly — a 4" cartridge in a 5" rail will leak dirty air around the media.
Updated July 2026 · 4 min read · United States
Symptoms
- Cabinet door label lists 20×25×5
- Dust increase after a year
Likely causes
- Expired media
- Wrong depth installed
What to do
1. Slide out the old cartridge
Fan off. Note the airflow arrow stamped on the old media.
2. Install the new 20×25×5
Arrow toward the blower. Latch the door fully.
Stop and call a pro when
- Door gasket is missing and the cabinet bypasses
Related guides
- Replace 16×25×4 Media — Swap a 16x25x4 deep-pleat media filter in an aftermarket cabinet — orientation, change intervals, and why it is not a 1" pad.
- Aprilaire 213 Replacement — How to replace an Aprilaire 213 media filter in 2210/4200/2200-series air cleaners, including orientation and change intervals.
FAQ
How often to change 5" media?
Often 6–12 months. Check at 6 months if you have pets or high runtime.
Need a licensed tech instead?
If the guide says to stop — or the part swap did not clear the fault — get free quotes from licensed local HVAC contractors.
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