Home Heating

Energy Myth: Turning down the thermostat doesn't save energy because it takes as much energy as was saved to reheat the house.

Fact: Heat escapes faster when there is a big difference between the inside and outside temperatures. When you turn down the thermostat the indoor temperature is closer to the outdoor temperature, therefore you lose less heat, the furnace runs less and you save a lot of energy.

Home Series Booklet: Home Heating (PDF)

No-Cost/Low-Cost Tips:

  • Dress warmly. Wear a sweater and cover exposed skin. Several thin layers also are effective because these trap small air pockets that provide thermal insulation.
  • Open south-facing window coverings during the day to let in free heat from the sun. See page 2 of Home Heating.
  • Close all draperies and shades at night to reduce heat loss. Drapes save energy only if they fit tightly around the window frame. This usually means a valance at the top, side guides and a weighted hem. See page 2 of Home Heating.
  • Remember to change the return air filter at least once every two months (once a month is preferable). Dirty air filters can increase costs by 10%. See page 3 of Home Heating and 30 Simple Energy Things.
  • Set the thermostat as low as comfortable and lower it when away from home or at night when sleeping. When it's 50°F outside and you turn the thermostat from 70°F to 65°F you reduce your energy costs by 25%. Recommended winter thermostat settings are 68°F during the day and 55°F at night. See pages 2 and 3 of Home Heating.
  • Check the ductwork in your attic or crawlspace to ensure it has not become disconnected or obstructed. See page 5 of Home Heating.
  • Don't let heat go up the chimney. Make sure the fireplace flue is closed when you are not using it. See pages 6 and 12 of Home Tightening.
  • Caulk, weatherstrip and seal inside cracks around windows and doors to prevent drafts. Also, check and seal holes in the ceiling and floor. Electric outlets and switches can let cold air into the house. Remove the outlet covers and insert special foam insulation underneath. Place insulating plugs in all outlets that are not being used. Outlet insulating plugs may be purchased at your neighborhood home improvement store. See Home Tightening and pages 40 through 46 of Home Energy Projects.
  • Do not block heating outlets or return air vents with furniture or other objects. See page 6 of Home Heating. Also, clean supply registers, baseboard heaters and radiators as needed. See page 3 of Home Heating.
  • Use removable rope or cord weatherstrip to seal cracks in windows that will be later be opened. This clay-like material is inexpensive and very easy to apply. See page 7 of Home Tightening.
  • Install an automatic setback thermostat. These cost about $50 but automate the setback times and amounts to make saving energy easier. See page 3 of Home Heating.
  • Keep your heating system tuned up to run efficiently. If your heating system is running inefficiently, 30 to 50% of the energy it uses is being wasted. Gas furnaces older than five years should be tuned every year. A simple tune-up can increase a furnace's heating efficiency by 5%. See pages 5 and 6 of Home Heating.


  • Leaks develop in all air ducts over time. Sealing the leaks in ducts can reduce heating costs by up to 20% with reductions of 10% extremely common! Check your ducts for air leaks. First look for sections that should be joined but have separated, then look for obvious holes. Seal ductwork with specialized duct mastic. The majority of products labeled "duct tape" are not suited for ducts. Look for duct sealing tape with the Underwriters Laboratories logo on it. Be sure that a well-sealed vapor barrier is on the outside of the duct insulation to prevent moisture buildup. Get professional help to insulate and repair all ducts. See pages 5, 6 and 7 of Home Heating.
  • If the thickness of your ceiling insulation is six-inches or less, add more. Depending on the type of insulation, a total thickness of 10 to 12 inches is enough in this climate (R-30 to R-38). Before insulating, make sure that all holes in the ceiling are sealed as well as any cavity that can move air from one part of the house to another. Check under existing insulation to make sure that there are no holes under it. Insulation does not air-seal, caulk and foam do that. See pages 8 - 11 of Home Insulation.
  • Insulate under the floor (if the basement is unheated). See pages 14 & 15 of Home Insulation.
  • If you've got single pane windows, install storm windows. For replacement windows or new construction, chapter 3 and appendix D of the Energy Efficiency Tune-up have easy-to-understand descriptions of the latest window applications and technologies.
  • If your house was built before 1970 then it probably needs wall insulation. Wall insulation in an existing home is expensive but a good investment in the long run. This will require a contractor. An excellent time to drill holes in the exterior walls is when adding or replacing you home's siding. All of the work will be under the new siding and the addition of the siding will only add to a well insulated wall. See page 16 of Home Insulation.
  • If your furnace is older than 15 years, it's probably time to replace it before it breaks or causes some problems. Newer furnaces are much more efficient so make sure that the new system is sized to meet the demands of your home-especially if some insulation and air sealing have been done. The correct sizing and installation of heating and air conditioning systems (including air distribution and air return) can lower the upfront purchasing cost, provide greater comfort, lower monthly utility bills for the homeowner and extend the lifetime of the equipment. Ask the A/C contractor for a Manual J analysis. See page 8 of Home Heating, and check out qualified Energy Star heating systems. SPECIAL NOTE: Bigger in NOT better! For more information on the importance of "right sizing" go to the "Bigger is not Better" link below.