Heating & cooling
Furnace filter replacement
A clean, correctly fitted filter supports airflow and helps protect heating and cooling equipment.
Recommended timingCheck monthly; commonly replace every 3–4 months
What to do
- Turn the system off at the thermostat.
- Locate the filter at the return grille or equipment cabinet.
- Note the printed size and airflow arrow before removing it.
- Install the same approved size with the arrow pointing toward the blower.
- Record the date and check it more often during smoke, remodeling, pet shedding, or heavy use.
Use the filter type and rating approved by the equipment manufacturer; an overly restrictive filter can reduce airflow.
Official guidance and sources
Product instructions and local requirements take priority for the equipment or material installed at your home.