Dirty air filters restrict airflow and reduce the heating system’s efficiency. Inspect your air filters once a month when the system is in use for heating or cooling. Clean or replace dirty air filters as necessary. The first step in inspecting your air filters is to locate and remove the metal panel covering the filter or filters. The cover panel should be located near the heating system’s blower. Next, slide out the filters. Clean or replace the filters with new filters of the same size. Slide the new filters into position according to the airflow directions on the filter. Finally, replace the cover panel. Regular inspection, cleaning and replacement of your furnace filters will reduce your heating bills and prolong the life of your heating unit.