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. 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.

Here’s how to maintain your forced-air system:

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 likely be printed on the frame’s edge. Make a note of it.

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

5) While you have the furnace open, it’s a good idea to vacuum out the area around the blower. If possible, slide out the fan unit and clean each fan blade with a toothbrush, then vacuum with a brush attachment on a vacuum cleaner.

6) Look for oil ports on the motor, normally located near the motor shaft. Most contemporary motors don’t require lubrication, but motors with oil ports should be lubricated once a year. If the motor has oil ports, apply two or three drops of non-detergent motor oil into each port (you may have to remove a cover plate to do this).

7) Look for worn belts between the motor and pulleys. If you see any, they will need to be replaced.

According to the Department of Energy, regular maintenance is the key to an efficient heating system. Dirty filters, clogged burner ports and improper settings can drastically reduce furnace efficiency. They recommend a yearly inspection by a qualified service technician and replacing or cleaning filters on a monthly basis. A permanent air screen or electronic air filter should be cleaned according to manufacturer’s recommendations. Properly maintaining your heating system—whether it’s a conventional system or a high-efficiency one—is the best way to ensure years of problem-free, economical, and comfortable heating.

Most heating systems operate reliably for a long time if they are well-maintained. Before you call a furnace technician for a repair or roll up your sleeves to do the work yourself, call your utility or check its Web site—in many areas, the utility company will send a technician to your home to check minor furnace problems for free.