Preparing your furnace for winter

Test the furnace before the first sustained cold weather, replace or inspect the filter, clear the mechanical area, and make sure intake and exhaust terminations are free of snow or debris when applicable. Confirm carbon-monoxide alarms are working and know where the furnace switch and water shutoff are located. Do not cover vents, bypass safety controls, or use an oven, grill, or outdoor heater indoors. If the furnace fails or smells of gas, leave the building and arrange emergency help.