To reduce the cost of heating your home throughout the winter... Install and use an automatic setback thermostat to reduce heating and cooling costs by 5% to 15%. Place reflectors behind radiators to redirect heat that goes into the wall back into the room, and save another 5%. (Aluminum foil over cardboard will do.) Insulate heating and hot water pipes that are exposed in areas you don't want the pipes to heat. Change furnace filters every month -- or more often if needed. Get a furnace tune-up to adjust and clean burners. Wrap the tank of a gas-burning water heater in a manufacturer-approved fiberglass insulating blanket. Replace worn-out thresholds under doors and weather stripping around windows. Lower the indoor temperature to save about 2% of heating costs per degree. Close the fireplace damper when not in use.If you never use the fireplace, seal it with a plastic bag stuffed with insulation. Close off rooms that are not in use, and lower the temperature in them.