We take care of an elderly person who constantly leaves the hot water running in his bathroom. This has, at times, completely drained our hot water tank. Where can we purchased faucets, like in some hotels or restaurants, that meter out the water and shut off automatically?

How about something like this:
Motion Activated Faucets Save Water : Green building and living - GreenStrides

If you'd like to maintain normal functionality, a motion detector and two solenoid valves. Someone must be in the bathroom for the water to run normally. If the installer is good, they can make it that when the timeout occurs after the motion ceases, it sounds an alarm. Caught!

Hi all:

Stratmando has presented some very useful faucets although they are primarily MOTION ACTIVATED.

Kiss has presented a very fun way to resolve your issue... :)

I, on the other hand, think you are really asking about METERED FAUCETS. Here, like in hotels, restaurants, etc. you want the person using the faucet to push to turn the faucet on and then the faucet will automatically shut off. These faucets usually come with the ability to adjust the time the faucet stays on.

Check them out at:

Metering and Self Closing Faucets

I recommend the Symmons down on the bottom right. Quick and easy to install and pretty reasonably priced compared to motion-activated faucets.

Hope that helped... ;)

MARK

I like the fun way comment. Thanks.

Sometimes you like to have lots of warm water in the bathroom at home. Infared sensors just for washing hands doesn't quite cut it when you want a glass of cold water or want to fill the basin to "wash up".

Thus the room PIR sensor that turns on valves for the water.

Combine that with a delay on break and another timer and a water flow meter and you have an alarm. Culpret caught.

This suggestion doesn't turn it off, but can be arranged.