Wash in cold water: About 90% of the energy consumed for washing clothes is due to heating the water. Unless you're dealing with oily stains, the warm or cold water setting on your machine will generally do a good job of cleaning your clothes. Switching your temperature setting from hot to warm can cut energy use in half for washing one load. Using the cold cycle when you can reduces energy use even more.


Fill it up: Clothes washers use relatively the same amount of energy regardless of the size of the laundry load, run full loads whenever possible.


Avoid the sanitary cycle: This super hot cycle, available on some models, increases energy use significantly, so only use it when absolutely necessary.


Activate the high spin speed option: If your clothes washer has spin options, choose a high spin speed or the extended spin option to reduce the amount of remaining moisture in your clothes after washing. This decreases the amount of time it takes to dry your clothes.
Use a drying rack or hang clothes outside: Air-drying clothes (indoors or outdoors) helps them last longer and saves energy.


Leave the door open after use: Front-loading washers use airtight seals to make sure no moisture leaks while the machine is in use. However, when the machine is not in use, this seal can trap moisture in the machine. Be sure to leave the door ajar for an hour or two after use to allow any of the remaining moisture inside the machine to evaporate. Make sure children do not climb into the machine while the door is open.


Always use HE (High Efficiency) detergent: Front-loading clothes washers are designed specially to use only High Efficiency detergent. Using regular detergent in a front-loading washer will create too many suds in the machine. This leads to decreased washing and rinsing performance. Over time it can lead to mechanical problems, and foul odors.

Source: EnergyStar.gov