Furnace Filter Care

Clean or replace a disposable furnace filter periodically during the winter--check the filter monthly. Brush and vacuum the heat exchanger surfaces every year, if recommended by your owner's manual. Before the heating season, clean the blower blades and seal any air leaks in ducts with several wraps of duct tape.

A little maintenance goes a long way toward keeping your forced-air equipment working properly. Start by cleaning or replacing the filter. With forced-air furnace systems, air returning to the furnace's blower first passes through an air filter designed to catch dust and debris and help clean the air before it's recycled to your home.

A good furnace filter can help reduce allergens but isn't designed to significantly improve air quality in your home. For that, you'll need a special air filter (talk to a heating specialist about this).

When typical filters become clogged with debris, they cut down on a furnace's efficiency and, over time, can cause parts to wear out faster. Change filters quarterly or sooner if they look dirty. Pleated fabric filters are a good, inexpensive choice for reducing dust and allergens.

Here's how to change a replaceable filter:

1) Turn off the power to the unit.

2) Look for the door or panel that conceals the blower; sometimes this is marked "Filter." Lift this door or panel off of its holding hooks or unscrew its retaining screws to remove it.

3) Standard filters are mounted next to or under the blower motor. Slide the filter out along its tracks. Check to see whether it is a disposable filter or intended to be cleaned and replaced--this should be marked on the filter's edge, along with directions for cleaning if applicable. If it's a disposable filter, its size will probably be printed on the frame's edge also. Make a note of its size.

4) Buy a replacement and slide it back into place, noting that arrows stamped on the side indicate the proper direction of airflow; be sure you face these in the proper direction.