Many central systems use disposable pleated filters in the furnace, air handler, or a return grille. Some window units and a few returns use washable screens. Confirm the type before you rinse anything.
Disposable furnace and AC filters
- Turn the system off at the thermostat.
- Open the filter slot at the furnace, air handler, or return grille.
- Note the size printed on the frame and the airflow arrow direction.
- Remove the old filter and bag it. Do not put a heavily loaded disposable pleated filter back after vacuuming.
- Install the new filter with the arrow pointing toward the furnace or air handler (with the airflow).
- Restore power and confirm airflow at the vents.
Washable filters
Only rinse a filter if the manufacturer labels it washable. Rinse with cool water from the clean side out, let it dry fully, then reinstall. Never run the system with a wet filter.
How often to check
Follow the filter maker and equipment maker guidance for your MERV rating and home conditions. Homes with pets, renovation dust, or long cooling runtime often need more frequent changes. The U.S. EPA notes that filters should be changed regularly and that the right schedule depends on the filter and household; see EPA guidance on air filters.
Need the right size?
Order replacements through our online filter shop, or ask us to confirm size and a MERV rating that fits your blower. If airflow stays weak after a new filter, request AC service or ask about duct cleaning.