How do I change my furnace filter?

Changing your furnace filter is one of the most important maintenance tasks you can do yourself, and it should be done every 1-3 months depending on the filter type and your home's conditions.

Start by turning off your furnace at the thermostat or the power switch near the unit - this prevents the system from running while you're working on it. Locate your filter, which is typically found in one of three places: in a slot along the return air duct near the furnace, inside the furnace cabinet itself, or behind the return air grille on your wall or ceiling.

Remove the old filter carefully - note the direction of the airflow arrows printed on the filter frame before pulling it out. Take a photo if you're unsure, as the new filter must be installed with arrows pointing in the same direction (toward the furnace). Check the filter size printed on the frame (like 16x25x1) and purchase the same size replacement.

In Ottawa's climate, you'll likely need to change filters more frequently during heavy heating and cooling seasons. If you have pets, allergies, or live near construction, consider changing filters monthly. Standard 1-inch pleated filters work well for most homes, while thicker 4-5 inch filters last longer but require compatible furnace systems.

Slide the new filter into place with the airflow arrows pointing toward the furnace, ensure it fits snugly without gaps around the edges, then restore power to your system. Mark your calendar for the next change - a clogged filter reduces efficiency, increases energy bills, and can damage your furnace by restricting airflow.

If you're having trouble locating your filter or notice your furnace is short-cycling frequently, it may be time for a professional tune-up to ensure everything is running efficiently through Ottawa's demanding winter season.