I live in an apartment with electric hot water. When I leave town for several days, I have been in the habit of shutting off the power to the heater at the breaker, and turning it back on when I return from my trip. I only do this on trips of at least 1 week, not 1or2 day trips.
My reasoning was that there is no point in paying to keep water hot, when I won’t be using any for several days or weeks.
It finally occurred to me that maintaining a constant temp probably takes less energy than the energy necessary to bring 40 gallons of cold water up to temp.
My query: Roughly how many days/weeks do I need to be out of town/power off to be in “net energy savings” mode, and to save more electricity than is consumed in re-heating upon my return?
The money you save will probally be the time the water is at (or pretty darn close to) room temp. So if you will be away long enough that the water will get to room temp and stay there a while you will be saving money. OTOH if you leave and turn it back on before it hits room temp then you might as well have left it on.
That said - the above might be for room/house heating not hot water.
Water heaters maintain a maximum temp. while on. Turning it off will save you considerably, esp. while on vacation. Water heating is a major part of your power consumption. When I don’t have need for hot water throughout the day, I’m in the habit of shutting it off. The water will heat from 35/50 degrees to 110 in less than an hour in my 40 gal. tank. If you have a newer super-insulated tank, it won’t matter so much.
Keep conserving that energy, piss of Dubya.
It doesn’t matter how long you’re gone, it will always save you money by turning the water heater off. The only downside is that when you return, your water won’t be piping hot for a while.
The heat that the hot water loses is proportional to the difference in temperatures of it and its surroundings. By reducing that difference (by letting the water cool off), you don’t lose as much heat. And it’s the heat that you’re directly paying for in your electric bill.
You have it right, turning off the water heater will save you money.
The water tank will lose heat all the time you are away, you wouldn’t leave an electric radiator on whilst you were out for a period of time would you ? and those are usually less than 1KWatt whereas your water heater will be at least 4KWatt.That is like leaving an electric fire on with 4 bars running!
IIf you want hot water ready for when you return I’d suggest fitting a timer set to a couple of hours before your come back.