from Angie in Milwaukee, WI:
#624
When leaving my home for extended periods, at what duration of an absence does it make sense to turn off my electric hot water heater, then turn it back on when I return?
If you’re gone for several days or a week it may make sense.
If you are gone for several days or a week, it may make sense. Turning off the water heater will always save energy; the concern is how convenient and how safe is it to turn the water heater off. After turning on the water heater it will take some time to reheat the water to 120°F. How long it takes to bring the water up to temperature depends on how big the tank is and how long the water heater has been off. In addition, bacteria may be more prolific in water that is not hot or has been hot for a short period of time, so you should wait a few hours between turning on the water and using the water.
There are some easier ways to save money on water heating. Electric water heaters are typically much more expensive to operate than those powered by natural gas or other fossil fuel, making an LP or natural gas unit half to a third less expensive. If you want to stay with electric, look into a high efficiency model. Installing a unit with an Energy Factor (EF) of 0.93 can save a significant amount of money.