Edward Reid wrote in
:

On Wed, 01 Dec 2010 12:42:17 -0500, Kurt Ullman
wrote:
So... any particular reason you shouldn't
turn off the water to the heater if you are not also going to turn off
the pilot?

Yes. If the WH does leak, including via a leaking hot water faucet,
and empties, the flame could damage the WH.

Wouldn't want to damage a leaking WH.

This is a near certainty
with electric WHs, not sure how likely with gas. You don't indicate
whether the kid was planning to turn off the inlet, the outlet, or
both -- if he doesn't know how to relight a pilot, perhaps he doesn't
even know which valve is which. If he closes both and leaves the flame
on, I think there's a high likelihood that the pressure relief valve
will trip, discharging water wherever it does.

Also won't save any energy.

I believe that most gas WHs have a "pilot" setting, which keeps the
pilot lit but does not allow the main flame to ignite. Same as most
gas space heaters. May even be required.

If the kid doesn't know how to relight the pilot, he should not fool
with the WH. If he doesn't trust the WH, he should call the landlord.

Edward