The debate over the best water heater setting continues. If the setting is too high, energy use results in high utility bills. If the setting is too low, bacteria may grow. Many homeowners set their water heater at 140 degrees (Fahrenheit). If you talk to an energy expert, you'll hear that 120 degrees is sufficient to provide for a family's hot water needs. Using the lower setting will save quite a bit of energy compared to the 140 degree setting.

Most dishwashers operate satisfactorily at the lower setting. Some state energy codes, in fact, suggest temperatures as low as 100 degrees for the proper setting since higher temperatures can cause scalding. This is a particular concern for children and older people who could be burned by water that is too hot in the bath or shower. Always check the temperature of the bath before getting in or putting a child in the tub. Run the water to a safe, comfortable temperature before getting into the shower.

Despite the advantages of the lower setting on the water heater, there may be drawbacks. Studies in recent years have shown that warm or tepid water systems can become breeding grounds for bacteria such as the type that causes Legionnaires' disease. Some engineers suggest that water heaters not be set below 122 degrees in order to prevent conditions that might foster bacteria growth.

Very recent research presents arguments on both sides of the debate. Because of the uncertainty, choose the setting that makes you most comfortable. If you are concerned about bacteria, keep the thermostat at the 140 degree mark, but be mindful of the setting. Water at this temperature can cause burns. On the other hand, a setting just above 120 degrees will save energy, and discourage health dangers as well.