Turning off electric hot water heater when not home?

[ZachUA]

I have heard of people putting a timer on their electric hot water heater so that it shuts off when not in use. I'm not sure how I would go about hooking up a timer to mine, but I could simply flip the breaker when I leave in the mornings. Currently I take 1 shower per day and it's in the mornings. Other than that I almost have no need for hot water.

Has anyone tried this? How long does it take the heater to get back to proper operating temperatures?

[Ryland]

They work great and are easy to hook up, or if you are unsure about how to do it you can pay a pro to do it and still get a return on your investment within a year or two.
If they are available for your voltage of water heater I would go with a digital timer so that you can have it come on lets say on every morning from 5am-7am (water stays hot for 3-5 hours after that) then on Friday and Saturday it also comes on in the after noon for an hour so you can shower before any evening weekend plans.

[ZachUA]

Excellent. I think I could install it myself. I may also install solar attic fan.

I found a problem yesterday...only the A/C is labeled in my breaker box! Everything else is blank. What electrician installs a breaker box and doesn't label 90% of the switches?

[ttoyoda]

What electrician installs a breaker box and doesn't label 90% of the switches?
90% of them, in my experience.

[Tony Raine]

i've been wondering about these timers as well. my wife and i each take a shower at around 5:30 to 6:30 each morning. we don't need hot water again until around 7 pm when we wash dishes. i also sometimes take a shower in the evening since i work either outdoors or in a metal building with no heat/air/insulation all day.

so would one of these timers be cost-effective for me? basically i need hot water 5:30-6:30 am, and around 7-8 pm during the week. would the whole tank re-heating twice a day be more efficient than keeping it on all day/night?

Originally Posted by ttoyoda

What electrician installs a breaker box and doesn't label 90% of the switches?
90% of them, in my experience.

yup, my house doesn't have a single breaker labeled. trial and error with a circuit seeker solved that

[ZachUA]

that stinks about the boxes. I may turn everything off for the short time I take putting the timer in.

Tony, here is some good info I found today:

http://michaelbluejay.com/electricity/waterheaters.html

specifically these tips:

1. (if your heater was made after 1998, it's probably not worth using a timer at all.) A timer for an old (pre-1998) heater will save about 25kWh/mo. for a family of two using 40 gallons a day with the heater off four to six hours a day, but only 14kWh/mo. for a family of four using 80 gallons a day.

2. Home improvement stores sell a special water heater blanket that you can put around your heater to help insulate it. This reduces energy use by 10-15% -- for a family of two, that's about 21kWh/mo., or $20/yr. at 8¢/kWh. The savings are only slightly less for a family of four.

3. When it's set on scalding hot you have to mix in cold water in your shower to lower the temperature, and why make your heater boil the water if you don't need it that hot? You can probably do with the temperature set to 120 degrees F or less.

[}{ead$hot Zod]

slightly off-topic

100% of the panels I've installed are labelled.........

I've been to Michael's website, it has a lot of good reading.

[Sp`ange]

Originally Posted by ZachUA

Excellent. I think I could install it myself. I may also install solar attic fan.

I looked in to solar attic (gable) fans. I didn't see savings advantage for my house. They're DC, only move about 700 cfm and cost three times more than an AC fan that'll move 1800 cfm. If you have a small attic space, it might work for you.

[fshagan]

Electric water heaters are insulated pretty well, so you probably won't save much by turning it off. 100% of the energy goes into the water as heat (or very nearly so), so the only losses you can save are "standby losses" from heat radiating out of the jacket. Because electric water heaters don't have a flue that tends to cool the water, they usually retain the heat very well.

If you turn it off after it is hot, leave it off for 8 hours and turn it back on, does the element have to come on to heat the water again? If it does, spend your money on insulating the tank, the pipes coming out of the tank, installing a "thermal trap" in the outlet pipe, etc. If the water in the tank is still above room temperature then you haven't lost all of the heat and you won't save much energy by waiting until you come home to turn the elements back on. The intermittent use of the elements during the day will come very, very close to the longer run you need when you turn the elements back on.

[Tony Raine]

Originally Posted by ZachUA

that stinks about the boxes. I may turn everything off for the short time I take putting the timer in.

Tony, here is some good info I found today:

http://michaelbluejay.com/electricity/waterheaters.html

specifically these tips:

thanks for the link! mines 2004 or newer, so looks like i need to just mess with temperature settings.