The Proper Water Setting for a Dishwasher

Getting Dishes Clean

• Keeping everyone in your family healthy depends on proper sanitation in the kitchen, including getting the dishes clean. Foodborne illnesses can result from unsanitary dishes or tableware. The heat of the water and dryer cycle of the dishwasher typically destroys most germs left behind by food residue.

The Temperature

• Modern dishwasher detergents, as well as greasy food residue, require the water in a dishwasher to reach at least 140 degrees for complete removal. You can avoid having to set your home water heater that high by buying a dishwasher with an added booster heater, which heats the water to 140 degrees Fahrenheit, even if the tap water comes out at 120 degrees Fahrenheit. You can buy a model with an automatic booster to raise the water temperature or one that requires you to set it before using the machine. Some boosters only operate in heavy-duty wash cycles.

Energy Efficiency

• The largest part of the utility bill associated with washing dishes comes from the energy costs for heating the water, federal energy experts note. Energy-efficient dishwashers marked with the Energy Star logo offer the greatest savings on utility costs. Keeping your water heater set at 120 degrees Fahrenheit saves energy and its costs, so having a heat booster on the dishwasher also cuts your utility costs. Your dishwasher puts most of its energy--around 80 percent--into heating the water, so load and use it efficiently to save money.

Safety Concerns

• Besides cleaning your dishes and keeping your utility bills low, setting the right water temperature also keeps you and your family safe. Scalds from hot tap water injure close to 4,000 people and kill a few dozen every year in the United States, according to federal statistics. Safety agencies urge people to keep their water heaters at the lowest effective setting for cleaning dishes, usually 120 degrees Fahrenheit.