Reducing Hot Water Temperature

If the hot water temperature controls in your home are set too high, you may be able to reduce your water temperature, and prevent energy and money from going down the drain. Reducing the temperature saves energy primarily by reducing the amount of heat that is lost out of the hot water tank (known as stand-by losses). If appliances such as clothes washers and dishwashers use hot water at the temperature supplied by the water heater, and do not mix this water with cold water to achieve a set hot water temperature, additional savings will occur. Here are a few tips and guidelines to help with cost-saving adjustments.

Temperature Guidelines

Check the temperature setting of your hot water tank by using a thermometer at a faucet near the tank (thermostat settings on water heaters are not always accurate). The following are guidelines for common activities using hot water.

Handwashing: 110° - 115° F

Showers: 110° - 115° F

Dishwasher Rinse: Residential-type dishwashers usually require 130° to 140° F water. Some models have built-in booster heaters that allow the water heater to be set at 110° to 115° F. Liquid soaps for automatic dishwashers are designed to work well at lower temperatures. Experiment with the water temperature at the dishwasher and choose the most economical setting.

Laundry: Most clothes can be effectively cleaned in either warm or cold water. In fact, hotter water can cause some stains to "set." Washing clothes in warm or cold water will not only save energy, but also prevent premature wear and fading of fabrics. Use a cold water rinse for all loads.

Adjusting The Temperature

Adjusting the hot water temperature is usually straightforward. A plumbing or mechanical contractor can make the adjustment, or you can do it yourself. With an electric water heater, the thermostat is usually located behind a coverplate, and can be accessed by removing a few screws (Many electric water heaters have two thermostats - one for the upper heating element and one for the lower. - Be sure to adjust both.). When turning down the setting on an electric water heater, be sure to shut off the power at the circuit breaker to avoid the danger of electric shock. If the thermostat dial is visible (as is the case with most gas water heaters), simply adjust it to the desired temperature.

You may find that your first adjustment results in inadequate hot water for your needs. Experiment with the setting to find a temperature that provides adequate hot water, while still minimizing wasted energy.