Lower the temperature on your hot water heater down to 120 degrees Fahrenheit (55 degrees Celsius).
This is the optimum temperature for your hot water heater. Most people don’t use water hotter than 120 degrees — indeed, water hotter than that can scald you or a child — and thus the energy needed to keep the water above 120 degrees isn’t used effectively. Lower the temperature, save money on your energy bill, and you’ll never skip a beat. Toss a water heater blanket over that hot water heater as well.
While most modern hot water heaters are well-insulated, some are insulated better than others, and many older heaters aren’t insulated well at all. A small investment in a blanket for your water heater will slowly and gradually save you money on your heating bill over time by keeping the heat in the water instead of letting it disperse slowly into your basement or utility closet.
The Department of Energy recommends being “careful not to cover the water heater’s top, bottom, thermostat, or burner compartment.” And of course, on-demand (or “tankless”) water heaters don’t require this treatment.