Heating and cooling

How to change a furnace filter

Find the filter slot or return grille described in your equipment manual. Read the size on the old filter and check the manual for the filter rating your system accepts.

Open the full filter guide Find Toronto HVAC contractors

A filter access cover on a vertical air handler held by thumb screws — Courtesy of Pacific Northwest National Laboratory and the U.S. Department of Energy Building America Solution Center. Image reuse terms. Re-encoded and metadata removed.

Match the filter and airflow direction

Turn the system off as the manual directs before opening the user-accessible filter slot.
Check the new filter’s size and airflow arrow. Point the arrow in the direction the air moves toward the blower.
Seat the filter flat and close the cover before restoring normal operation.

Call for service if the filter has collapsed into the unit or reaching it requires opening an electrical or combustion compartment.

Keep checking the heating system

Check a furnace that isn’t heating Carrier’s filter replacement guide