When filters become clogged with debris, they cut down on a furnace’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 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 furnace’s filter, 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.