Each 10 degrees reduction in water temperature generally saves 3 to 5 percent on water heating costs.
T urn off the electricity to the electric water heater at the main electrical panel.
Remove the water heater thermostat covers. Use a screwdriver to reset both top and bottom thermostats to 120 degrees, the optimum temperature for water heating comfort and efficiency. Replace the insulation and the thermostat panel covers and restore power. Costs and savings estimates for these tips are intended as a general guide. Based on typical usage and typical installations, individual savings and results will vary depending on weather, usage patterns, housing stock, family size, product use and other factors.