Your home may be your castle, but you don’t have to pay a king’s ransom to keep it warm. By Pat Mertz Esswein, Associate Editor From Kiplinger's Personal Finance, February 2014 1. It’s cold inside. Sitting in your overcoat with the thermostat at 78 degrees? You could have a problem. If you haven’t already sealed out wintry drafts, do it now. Apply weatherstripping and clear plastic film over windows, and add door sweeps. To find out where else your home is losing energy, hire an energy auditor ($250 to $600) who is certified by Home Performance With Energy Star or the Building Performance Institute.See Our Slide Show: 15 Ways to Prepare Your Home for Winter Vidhya Nagarajan 2. Your furnace could be kaput. You should schedule an annual furnace tune-up by a member of the Air Conditioning Contractors of America ($80 to $100 per unit). But if the furnace is more than 15 years old, you could be sending one-third to half of the fuel it uses up the flue. Replace it with a new, Energy Star–qualified gas- or oil-burning furnace that runs with at least 90% to 95% efficiency. The cost of swapping an older gas furnace for a high-efficiency one starts at about $2,000 to $6,000, but it could cost $7,000 to $12,000 or more, depending on model and capacity, according to CostHelper.com. If your old furnace was originally rated for 78% efficiency and the new unit is 90% efficient, you’ll save about $14 for every $100 you currently spend on fuel, says the Department of Energy. 3. Take a holistic approach. If your air conditioning is more than ten years old and uses the furnace’s blower to move cooled air through your home, replace both units simultaneously. That will decrease your total cost by about one-third compared with staggered installation, says Glenn Hourahan, senior vice-president for technology with the ACCA. If you live in a moderate climate, you could install a “dual fuel” system, with a heat pump and gas furnace, for greater savings. The heat pump will heat and cool your home, say, from spring through fall. In the winter, a “smart thermostat” will fire up the furnace when outdoor temperatures drop below 40 degrees. 4. Who you gonna call? For installation, maintenance or repair, look for a heating, ventilation and air conditioning (HVAC) contractor who is a member of the ACCA and employs technicians certified by North American Technician Excellence. The best contractors subscribe to ACCA’s Quality Installation Checklist. 5. Roll in R2D2. For those rooms where you still need to wear furry slippers and a Snuggie, consider either a convection or radiant portable space heater (about $30 to $150). For greatest efficiency, match the heater’s size to the rooms where you’ll use it, and get one with thermostatic control. For safety, choose an electric model with the Underwriter’s Laboratory label and a tip-over safety switch that will shut off the unit if it falls over. 6. And don’t forget. . . Capture the sun’s warmth by opening shades on south-facing windows during the day. And cover all windows at night. Use a programmable thermostat to set back the temperature ten to 15 degrees when you’re away or asleep. Clean or change your furnace filters once a month or as recommended. If you have a fireplace, close the damper and doors when it’s not in use.