Filter replacement
How to Replace a 16×25×4 Media Filter
4" media cabinets cut restriction versus a packed 1" filter. Replacing the cartridge is still required — usually every 6–12 months — and the depth must match the cabinet exactly.
Updated July 2026 · 4 min read · Canada
Symptoms
- Media gray throughout the pleats
- Door label shows 16×25×4
Likely causes
- Annual media overdue
- Wrong depth ordered
What to do
1. Open the media cabinet door
Turn the fan off. Release latches and slide the cartridge out on its rails.
2. Insert the 16×25×4 with arrow toward the blower
Expand/seat per manufacturer instructions. Close and latch so there is no bypass.
Stop and call a pro when
- Cabinet was retrofitted poorly and leaks air at the door
Related guides
- Replace 20×25×5 Media — Replace a 20x25x5 thick media filter used in many Honeywell/Resideo-style cabinets, with orientation and interval tips.
- Filter Size Guide — How to read furnace filter dimensions, why nominal vs. actual sizes differ, and which MERV rating to buy without starving airflow.
FAQ
Can I put a 1" filter in a 4" cabinet?
Not effectively — it will leave a huge bypass gap. Buy the matching depth.
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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