When filters become clogged with debris, they cut down on a heating system’s efficiency and, over time, can cause parts to wear out faster. A permanent air screen or electronic air filter should be cleaned according to the manufacturer’s recommendations. Disposable filters should be checked periodically—monthly during winter—and cleaned or changed as needed. Pleated fabric filters are a good, inexpensive choice for reducing dust and allergens.
In addition to regularly inspecting your heating system’s filter, brush and vacuum the heat exchanger surfaces every year if recommended by your owner’s manual. Before heating season, clean the blower blades and seal any air leaks in ducts with several wraps of duct tape.
Here’s how to change or clean a 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 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 information should be marked on the filter’s edge, along with directions for cleaning, if applicable. If it’s a disposable filter, its size will be printed on the frame’s edge. Make a note of it.
4) Buy a replacement, and slide it into place, noting that arrows stamped on the side indicate the proper direction of airflow; be sure you face these in the proper direction.
5) While you have the furnace open, vacuum out the area around the blower. If possible, slide out the fan unit, clean each fan blade with a toothbrush, and then vacuum with a brush attachment on a vacuum cleaner.
6) Look for oil ports on the motor, normally located near the motor shaft. If the motor has these, apply two to three drops of non-detergent motor oil into each port (you may have to remove a cover plate to do this). Most contemporary motors don’t require lubrication, but motors with oil ports should be lubricated once a year.
7) Look for worn belts between the motor and pulleys.
Ideally, you would want to have an expert inspect your heating system at least once a year.