When to Shut Off Your Water Heater

| 10/8/2010 10:39:00 AM

Is shutting off my hot water tank for a substantial portion of the day a good way to save energy? I’m considering turning it off at night, and also during the day when I’m not home. Is this a good idea? 

Turning off an electric (not gas) water heater for some portion of the day has promise in terms of saving energy. However, this particular timing scenario is a nightmare for an electric utility in terms of supply and demand. Here’s why: Most people tend to leave for work around the same time in the morning and arrive back home around the same time in the evening. Electric utilities experience a significant jump in demand in the mornings, normally from around 6 to 8 a.m., and then an even larger spike in demand when people start to arrive home and take showers, make dinner, turn on the air conditioner, etc. Late-afternoon demand peaks can start as early as 3 p.m. and continue until 8 or 9 p.m., depending on weather conditions and other factors. Why does this matter? One reason is that if too many people are drawing electricity at the same time, utilities can’t keep up, and this results in brownouts, blackouts or rolling blackouts.

On a side note, I’m convinced electric utilities secretly dread the wider use of plug-in hybrids and all-electric vehicles because they expect most folks to plug them in when they get home, drastically spiking energy demand. I predict there will soon be a major campaign to have all plug-in hybrids and electric cars charged during the night hours and not at dusk or dawn. 

In short, while the idea of turning off an electric water heater is a tempting one, I recommend adjusting the timing of the charge cycles. Buy and install a 220/240-volt timer, which should be easy to find online. I suggest turning the water heater on anytime after 10 p.m. Then have the timer shut off the unit before 6 a.m., and turn it on again from 10 a.m. to 3 p.m. This setup leaves the water heater off for about 11 hours a day, which should be a significant energy savings. 

— Kenneth C. Riead, certified energy manager, Hathmore Technologies

For more advice on saving energy with this method, go to www.EnergySavers.gov, and search for “water heater timer.”

2/11/2013 7:27:59 PM

I am doing something similar to this. Most dishwashers have a delay function that allows for a 2 - 4 hour delay between the time it is turned on and the actual time it runs. So, during the week I set the dishwasher to come on after after a 4 hour delay when I am headed to bed at 10 pm... and at that same time I turn the water heater. Then, the dishes are done when I get up in the morning, and there is plenty of hot water for our showers. I turn it back off in the morning at about 7 am as I leave for the day. This seems to work well for us until we come to the weekend when we are wanting to do laundry. I leave it on all weekend to take care of that demand. I was hoping that I was not damaging the water heater by doing this, and from what I have read I am not.

Subscribe Today - Pay Now & Save 64% Off the Cover Price

Money-Saving Tips in Every Issue!

Mother Earth NewsAt MOTHER EARTH NEWS, we are dedicated to conserving our planet's natural resources while helping you conserve your financial resources. You'll find tips for slashing heating bills, growing fresh, natural produce at home, and more. That's why we want you to save money and trees by subscribing through our earth-friendly automatic renewal savings plan. By paying with a credit card, you save an additional $5 and get 6 issues of MOTHER EARTH NEWS for only $12.95 (USA only).

You may also use the Bill Me option and pay $17.95 for 6 issues.

Canadian Subscribers - Click Here
International Subscribers - Click Here
Canadian subscriptions: 1 year (includes postage & GST).

Facebook Pinterest Instagram YouTube Twitter flipboard

Free Product Information Classifieds Newsletters

click me