Water Shut Off

Jul 26, 2008 13 Replies

Is it safe to shut off the main water valve to a house, and put the water heater on "Low"? We will be leaving the house unoccupied indefinately.



My concern is the the water evaporating in the 40 gallon tank, and the tank being damaged. How long before I need to worry that this will happen with water shut off?


... Just turn the water heater completely off...there's no reason if the house is unoccupied to leave it on. When cold weather arrives, need to arrange for not freezing any standing water, of course, ...

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On Sat 26 Jul 2008 12:31:43p, Luca told us...

Do you live in a climate where there are freezing winters? For more reasons than one, you should leave your furnace set to at least above freezing, say 40-45 degrees F. In that case, I would simply turn the tank off altogether.

If you don't plan on leaving the furnace on, you should turn off the tank and drain it, as well as drain as many interior pipes as possible.

I would never turn the water off to the tank and leave it turned on.

That's a long time! Are you planning to turn off the power/gas/utilities??

If 'indefinite' is more than several months, I'd worry about plumbing traps drying out and venting sewer gas into the house. I'd consider blocking the drains and draining the supply system.

T

Let me rephrase...simple specific question

How long is it safe for water heater to be on low if tank is full but main water is shut off (absence is a few months in the northeast), now until maybe October. I don't want tank to be damaged.

Turn it off completely. If you leave water in the tank and heat it, it will try to expand. It *probably* won't hurt anything, but 40-50 gallons of water on your basement floor isn't fun.

Like others have said, either drain the water down completely, or else leave the furnace on a low temperature to keep the house from freezing and have a friend come by and check it every now and again.

nate

Luca wrote:

Ad an RV antifreeze into the traps. Some folks suggest vegetable oil to slow evaporation of the traps. The OP is vague in the time frame.

Where is house, whats indefinatly, turn off gas at meter turn off water at street. If it freezes there winterise all traps and drain toilet and pipes and heater. Leave lights on a timer.

Let's rephrase the answer: Turn the water heater off if the house is unoccupied.

Yes, it's safe. Just leave the WH on 'pilot' to keep moisture out of the plenum.

s

Does anti-freeze delay the drying out?

Just turn it off. Lighting a water heater isn't rocket science. Also check your home owner's insurance; many won't insure an unoccupied dwelling, and it would be bad to get damage and find it out the hard way.

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