Even with a constant flow of information about energy efficiency, homeowners make major heating mistakes that end in higher electric bills and larger environmental footprints. Here are 10 of those errors, with the cause and effect of each decision.

1. Maintaining a constant temperature

Cause: A persistent myth suggests that you can save energy by leaving the house at a comfortable 68 degrees (a widely recommended winter setting), even when you are sleeping or away at work. The idea is that it takes more energy for the furnace to reach a comfortable temperature than to maintain that temperature.

Effect: Instead of opting for a heating repair service to fix up your old furnace, you could miss out on significant potential energy savings by not using a programmable thermostat and adjusting the temperature overnight and during the workday. Though the impact of adjusting the thermostat varies based on your climate and other factors, studies show that knocking the temperature down 10 degrees for eight hours per day can cut heating bills by 5 to 15 percent. Sure, the furnace will cycle on for a longer period to return to the more comfortable temperature, but it will be far outweighed by hours of savings when it didn't have to work as hard.

2. Cranking up the temperature to warm the house

Cause: You come home in the middle of the day to a cold house. You want to warm it back up to 68 ASAP, so you crank the dial up to 78 to get the furnace working harder and faster.

Effect: No time is saved in reheating the house. Most furnaces pump out heat at the same rate no matter what the temperature -- they just cycle on for a longer period to reach a higher temperature. The furnace will take the same amount of time to return to 68 degrees regardless of the thermostat setting. By cranking up the thermostat, you are likely to overheat the house past 68 degrees and waste energy. Just reset the thermostat to 68, make some hot chocolate and wait.

3. Closing off vents in unused rooms

Cause: You don't want to waste energy heating rooms you aren't using.

Effect: Again, this just wastes energy and makes your furnace run inefficiently because it changes the air pressure in the whole system. Experts recommend never shutting off more than 10 percent of vents. Sealing your ducts is a more efficient way to save energy.

4. Using the fireplace

Cause: You found some free firewood on Craigslist and think you can burn up some free heating energy while enjoying a romantic fire.

Effect: While we can't make any promises about increased romance, we can predict increased energy bills. An open fireplace flue may suck more cold air into the house than the fire can radiate into the living space.

5. Using electric room heaters

Cause: You spend most of your time in a couple of rooms, so you figure you will just heat them with space heaters.

Effect: This could lead to higher energy bills and greater fire risks. Generally, a central gas heating system is cheaper and more efficient than a set of electric room heaters. Electric heaters also can be a fire hazard. There are exceptions: a single energy-efficient space heater in a small, well-insulated room can save energy if the central heater is switched off.

6. Switching to electric heating

Cause: Electric heaters are more efficient than fuel-based systems, so they must be cheaper and better for the environment, according to this popular idea.

Effect: In most areas, simply switching to electric heat leads to higher energy bills and a bigger carbon footprint. Your heater may be more efficient, but most U.S. homes are still linked to coal-fired power plants. These coal plants and their transmission systems are extremely inefficient. Of course, it's a different story if you have a large photovoltaic solar array or your utility company uses renewable energy.

7. Replacing the windows

Cause: Those big pieces of glass get so darn cold. They must be the reason your house is so drafty.

Effect: You could spend a lot of money to only take care of part of the problem. Windows must be installed properly to avoid drafts, gaps and leaks. Moreover, more heat is typically lost through poorly insulated walls and ceilings than through windows.

8. Replacing the furnace first

Cause: You blame high energy bills on an old, inefficient furnace.

Effect: Your energy bills will still be higher than necessary if you don't start with cheaper, smaller upgrades to improve the energy efficiency of your home, such as caulking around windows and doors and adding insulation.

9. Upgrading to the most efficient furnace on the market

Cause: You want the sleekest, most energy-efficient furnace available because it will be the most cost effective as well.

Effect: You may end up replacing an oversized furnace with another (albeit more efficient) oversized furnace. The U.S. Department of Energy reports that most U.S. homes have oversized HVAC systems. Again, insulate and weatherize to maximize efficiency, then get the smallest system that will comfortably meet your heating needs. Also make sure you hire an HVAC professional to install it.

10. Using incandescent light bulbs for heating

Cause: Incandescent bulbs give off more heat than light, so they must be warming up the house.

Effect: It is hard to see this logic as anything but a weak excuse for holding on to the Edison bulbs rather than switching to CFL and LED lighting. In fact, one German entrepreneur is marketing incandescent bulbs as "heat balls" to skirt EU laws against the old-style bulbs. However, I doubt he is keeping cozy this winter simply by sleeping with the lights on.

Updated December 14, 2017.