MANY EMPTY nesters close vents to rooms they don’t use, believing they’re saving money on heating. It might save in the short term, but long term, the furnace will have more issues. “It’s trying to heat your whole house, and you’re restricting airflow,” says Jon Gilbertsen, an air quality expert and vice president of Chris Heating & Cooling in West Chicago, Illinois. An easy fix is opening at least 90 percent of the vents. —Liza N. Burby

For more on saving on home maintenance, go to aarp.org/homefixes