On Tue, 9 Nov 2010 21:46:44 -0800, "Steve B"
wrote:

you are not
at home. A lot of water can flow before you are aware of it. There is a
device that will shut off your water if it flows a lot, or is it when you
set the device to alarm, I'm not sure, but there is something you can buy to
protect your house from a catastrophic flood in case of failure. Still, it
takes a bit to kick in, and in that time, hopefully the drain will take the
catch pan's water out.

WATTS makes suck a device. *

My furnace is in the attic with a drain pan, etc. It has a similar
device for water detection.

_FloodSafe™ Water Detector Shutoff_

The site has a video or search youtube.

Features
•Shuts off both the water and power supply to the water heater upon
detection of a leak or malfunction
•Testable and resettable device
•Full flow valve, complies with plumbing codes
•Visual and audible alarms alert owners to leak condition
•Contacts for connection to monitored alarm systems
•No special piping required
•Models for gas, electric and oil fired water heaters
•Available for ¾ and 1 in. piping