When inspecting a furnace during a home inspection, I typically find that most people do not change their furnace filters at regular intervals. Replacing your furnaces air filter at regular intervals is the first step in keeping your furnace running properly. The furnace filter's main purpose is to keep soot, dust, pollens and other particle contaminants out of the air in your home. Clogged and dirty air filters result in your furnace blower having to work harder. This makes your furnace more costly to operate and will shorten its lifespan.
Check your owner's manual for the proper size and type filter for your furnace. Furnace filters vary in size, and it is important that you use one that is sized for your furnace. If you do not have access to the owners manual, you can sometimes find the filter information on the inside panel of the furnace. If the information is not provided on the furnace, you can try contacting the Rochester or Southeastern MN heating company that supports your furnace brand. Purchasing your furnace filters by the case changing more convenient.