Water Heater with Water Off

[Rich]

Any ideas on how long it will take a 40 Gal electric water heater to have a problem with the water supply shut off, pipes drained but water heater full, and electric still on? Or will it not be a problem at all if the water heater was not drained? What would be the worst case consequences?

I'm 4 hours away or I would just shut the power off.....

Thanks for any input, Rich

[Edwin Pawlowski]

If the water is still in the tank, there should be no problem at all.

[Toller]

If the pipes are drained the air in the pipes will compress as much as necessary, so nothing at all can happen. Well, at least nothing more than normal.

[Rich]

Thanks Edwin.... All I did was drain the water in the pipes by opening a lower level sink faucet and venting from 2nd floor so I am pretty sure the water heater is still full. Don't think it could have syphoned the tank. The property is in cold country and I wanted to shut off the water and drain the pipes in case the heat went off so I would only have to deal with the water in the house if there was a problem. I was in a rush and said to myself, I'll leave the water heater on so I don't cause thermal expansion and contraction which I was afraid might lead to cracks in pipes that have been hot for 20 years. Half way to our destination.... I started to think about the tank loosing water from heating with none to replace it. I can drive up and back tomorrow (8 hours) if I have to but can't go back until after Christmas if I don't go tomorrow. Do you think it would hold for

5 days?

Thanks, Rich

[Bob M.]

You're worrying too much. I live in Montana and when I go on vacation (two weeks long this past Thanksgiving; it got to -10 here then), I just turn the water main off and set the (gas) water heater control to "pilot". The house is kept at 55 during that time and in the unlikely event that a pipe does break, the water is shut off so there won't be much damage.

[Rich]

Thanks for all the input.... and you're right, I probably do worry too much. We just bought this house last June and it's in NY on the Canadian boarder so it can get cold up there too which is why I shut the water off to minimize damnage if the power goes out and we have no heat.

well with the power to the water heater on. I was worried about the water in the water heater vaporizing and emptying itself but in the essentially closed system it really has nowhere to go, the air in the pipes will compress a bit from the vapor pressure and everything should be fine.

For the future, for week long trips.... after turning the water to the house off and draining the pipes.... better to leave the power to the water heater on - or shut it off??? What do you think?

By the way... your responses have saved me a very long day, Thanks!

Rich ============================

Bob M. wrote:

[trader4]

How is leaving the water heater on going to have any effect on pipes which are 20 or 40 ft away and full of air? Hopefully, all the water heater is doing is keeping the water in the tank hot, with some waste leakage to pipes within a few feet. I would have just shut it off.

Half way to our destination.... I started to think about the

[Rich]

[jbgreig]

For what it's worth, I have a beach house and an electric water heater. I always turn off the water, drain the pipes, and leave the water heater on.

Never had any problem. And I have been known to leave it that way for months at a time.

I wouldn't worry about it.

Rich wrote:

[hallerb]

What hPPENS IF A ELECTRIC WATER HEATER HAS A LEAK with no incoming replacement water? I assume the elements would burn out?

[Rich]

Great to have a response from someone actually doing it this way with no problems.... Exactly my situation.

Thanks, Rich ====================================

[e-mail] wrote:

[Rich]

[Goedjn]

Probably. But it might just sit there and glow like a stove element for a month or so, until you get your next bill and wonder why it's $13,276 US.