Should we shut off our water heater until we need it?
We live in a single-family home that is four years old. Our electric water heater is in the basement. I am very frugal with energy and wonder if I would save anything by turning on our water heater only when we need hot water. We take showers every other day, use the dishwasher every other day and use the washing machine once a week.
Reply: Water heaters maintain water temperature at about 120 degrees so that it is available when you need it. The water in the tank does use energy to maintain that temperature once it is achieved. If the water heater is shut off and used only every other day, then you will allow the water in the tank to reach room temperature. When you turn on the water heater, it will need to raise the temperature of the water from room temperature to 120 degrees. That could be a difference of 50–60 degrees, depending on the temperature in the basement. So in effect you will be using energy to raise the temperature of 40–50 gallons of water 60 degrees.
My recommendation would be to keep the water heater on at all times and make sure it is operating at peak efficiency. Install a water heater blanket to increase the insulation value of the tank. (If you feel warmth when you touch the tank, heat is escaping.) A water heater blanket will reduce the tank heat loss. Water heater blankets can be purchased at home improvement stores for about $20.
Install pipe insulation on the exposed hot water supply pipe in the basement and on the first 3 feet of the cold water supply pipe. Make sure the water temperature in the tank is set at 120 degrees or less. If the hot water coming out of your faucet is too hot to touch, then the water temperature setting on your heater is set too high.
The energy used to maintain the water at the desired temperature should be about equal to the energy you would use to heat the water in the tank if it were shut off every couple of days.
Hot water is a convenience and should be used efficiently. You also use hot water for such daily activities as cooking, hand washing and cleaning.