Most of the energy used by a dishwasher is for water heating. The Energy Guide label estimates how much power is needed per year to run the appliance and to heat the water based on the yearly cost of gas and electric water heating. When it is time to buy a new unit, look for the ENERGY STAR label.

Appliances account for about 20% of your household's energy consumption, with refrigerators and clothes dryers at the top of the consumption list.

Check the manual that came with your dishwasher for the manufacturer's recommendations on water temperature; many have internal heating elements that allow you to set the water heater to a lower temperature.

Scrape, don't rinse, off large food pieces and bones. Soaking or re washing is generally only recommended in cases of burned-on or dried-on food. Be sure your dishwasher is full, but not overloaded.

Don't use the "rinse hold" on your dishwasher for just a few soiled dishes. It uses 3 to 7 gallons of hot water each time you use it. Let your dishes air dry; if you don't have an automatic air-dry switch, turn off the control knob after the final rinse and prop the door open a little so the dishes will dry faster.

Remember that dishwashers use less water than washing dishes by hand, about 6 gallons less per load; they also use hotter water than you would use if you were washing the dishes by hand, so they can do a better job of killing germs.