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Water Main Shut off and Electric Hot Water Heater

Posted by mrmichaeljmoore (My Page) on
Wed, Jan 6, 10 at 13:03

I have a question regarding turning off the main water supply to the house but leaving the hot water heater on. The water heater is a Whirpool ELECTRIC water heater. I think it is 40 gallon.

Here's the backstory: I came home last night to find that the supply line to my basment utility sink had worked its way loose, dumping a few inches of water onto my basement floor.

Needless to say, I am now a bit paranoid about leaving the house and coming home to find a pool in my basement.

So, I was thinking that when I leave for work in the morning, or go away for the weekend I will turn off the well pump switch and close the ball valve at the bottom of the well retention tank....thereby if I do get a leak, only what is in the lines will come out...

But, I remember reading somewhere that turning off the water supply, but leaving the hot water heater on could cause a problem. Something about evaporation in the water heater tank??

So, here are my questions:

1. If I decide that everytime I leave the house, I will turn off the main water supply to the house, should I turn off the breaker to the water heater?
2. How long can the tank sit powered on, but with the water supply closed?
3. Would I need to turn it off daily when I leave for work or only when I go away for a few days?



Follow-Up Postings:

RE: Water Main Shut off and Electric Hot Water Heater

YOu just need to do some home maintainence and inspect your individual fixture shutoff valves and flexible supply lines. They aren't "lifetime" products and occasionally need replacing. In fact, not using them is one of the direct reasons the shut off valves tend to corrode. Going around and shutting off shut off valves and inspecting the lines should be part of an semi annual maintainence schedule, but most people don't undestand maintainence and end up having to deal with repair instead. You should flush your water heater semi annually as well.

If you shut off your water supply, you'll need to shut off your water heater as well. Depending on the age and insulation level of your hot water tank that can lead to some long lead times to get hot water when you return. If your pipes are in good shape and you do periodic maintainence of all fixtures and valves, then this is an unnecessary inconvenience to you to perform every day. Now for vacations, that might not be a bad idea.

RE: Water Main Shut off and Electric Hot Water Heater

If anything happens to allow an electric water heater to expose a heating element the element will be destroyed nearly instantly.

Gas units are not as likely to be damaged, but can still overheat without a full tank.

Maintenance is less work than paranoia.

RE: Water Main Shut off and Electric Hot Water Heater

Actually, after futher review of what happened, it was maintenance that possibly (kinda sorta) contributed to the water leak.

The day before the leak, I was doing maintenance on my washer and dryer. I was cleaning the lint from the dryer vent. Also, I was cleaning out the washer tub.
I think I must have moved the utility sink a bit and caused the pex supply line that goes to the sink to move a bit, maybe causing it to loosen and then the heat and water pressure built up and popped the hot water supply line out of the bottom of the faucet connection. Either that or the rubber o-ring just gave out from the heat and water pressure.

So, I changed both lines to the steel braided type that I have on my washing machine supply lines. This should hopefully prevent any further issues.

And, yes, live wire oak, although you seem to assume I do not do maintenance around my house, I do indeed regularly perform maintenance around my house, to include: flushing the water heater twice a year, cleaning the dryer vent, cleaning the gutters, cleaning and servicing my water softener, changing the carbon and sediment filters for my well water, prepping and staining my deck, lawn/landscaping maintenace, maintenance of lawn equipment (riding mower, trimmer, blower), maintaining and cleaning of pellet stove, maintenance on two automobiles....etc...etc...etc...

I guess I have to add inspecting supply lines to that list.

And, yes, brickeye, I could not agree with you more. Maintenance is less work than paranoia......that is why I try to do as much as I can around my house to avoid the catastrophes.....


RE: Water Main Shut off and Electric Hot Water Heater

As long as the water heater doesn't drain you will be fine.

RE: Water Main Shut off and Electric Hot Water Heater

The water company shut the water off today to do repairs in my subdivision without notifying anybody. Last year this happened and fried my heating elements. This time just today 5/4 they did it again. I turned off the hot water heater. I then turned it back on when the water came on. No hot water again. Did it fry them again. We live in a 1997 oakcreek mobile home and just replaced two heating elements in a 40 gallong tank last year. Help could this be the problem AGAIN. Thank you

RE: Water Main Shut off and Electric Hot Water Heater

I was putting a new sink in my kitchen last night I shut off all water to my house and water heater in the basement because the hot wouldnt stop leaking at the sink after I was through installing the faucet I turned all water back on only to discover I have no hot water throughout the housr any tips on how I might get the hot water flowing again

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