The Trane XV80 is factory installed with a reusable filter designed to be cleaned and reused. A furnace works by drawing in ambient air that it heats and forces through ductwork in the home, warming the air inside. To do this efficiently, the furnace filters should be kept clean to allow maximum airflow into the blower.
Locate the blower door on your XV80 furnace. The door is identified by the louvres on the outside.
Turn the two latches on the blower door a quarter turn to release the catch and open the door. If the blower door is partially blocked and cannot be opened all the way, tilt the door open 2 to 3 inches and pull up and out at the angle of the door to remove.
Remove the filter. If the filter is bottom-mounted (underneath the blower), simply slide the filter out. If it's in side-mounted brackets, push on the outside edge of the filter to release the retaining brackets and slide out the filter.
Use a vacuum cleaner hose to remove dust and debris from both sides of the filter.
Reinstall the filter. Slide a bottom-mounted filter back into place, insert the end of the filter with rounded corners first. For a side-mounted filter, insert the back end of the filter into the back clip, then bow the filter slightly until the front end fits under the front clip.
Close the blower door and secure by turning the two clips back to their original position. If the door was removed, replace by sliding the bottom end into the slot at the bottom. Close and secure the latches.