Furnace filter routine

Plain House Manual

Filter slots in the home: ________________Look day each month: ________________Fall check-up booked for: ________________

Done	Item	Date	Notes
Set up the record, once
	Every return grille opened and checked
	Each slot numbered, place written down
	Size read off the frame, or slot measured
	Frame and airflow arrow photographed
	Size and arrow written on the duct
	One filter bought and fit tested
	Year of spares bought, stored flat
Every month
	Each filter slid out and looked at
	Held next to a white sheet of paper
	Dirty filter changed that day
At each change
	System off at the thermostat
	Arrow matches the photo
	Edges felt for gaps, system back on
	Date written on the new frame
	Change log row and next window filled
Once a year, early fall
	Spares counted for each size
	Order written for the year ahead
	Heating check-up booked and logged

Source: EPA, Guide to Air Cleaners in the Home, checked October 9, 2026. plainhousemanual.com/records/furnace-filter-record/Filter records and changes only, not HVAC repair, service or air quality advice.

Photos: benjamin lehman / Unsplash