Furnace filters purify and clean the air we breathe in our homes. They efficiently trap animal dander, dust, pollen, allergens and other particles that may cause respiratory problems. Not only do they keep the air healthy that we breathe, furnace filters also protect our furnace from damage. The filter is located between the return air duct and the furnace blower, typically right where the return air duct attaches to the furnace cabinet. Coleman furnaces are no different than any common residential furnace with respect to furnace filter location and the frequency that the filter needs to be changed.
Turn the thermostat to the "off" position to prevent your Coleman furnace from turning on.
Go to your furnace's location and find where the return air duct connects to your furnace. The return air duct will connect to either the side of the furnace or the bottom. Look for a slot in the duct. This is where the filter is located.
Pull the filter out of the return air duct. Note the size that is listed on the furnace so you can purchase the appropriate replacement size. The sizes listed are the height by width by thickness. (i.e. 16x25x1).
Slide your new filter into the slot on the return air duct. Ensure the arrow that says "airflow" is pointing toward your furnace.
Turn your thermostat back on and set it to your desired setting. The new filter will function at full capacity for 90 days.