On The New This Old House I saw an episode that put a 2 inch pan underneath the water heater, installed a remote sensor that detects water in the pan and at a certain depth triggers a new shutoff valve in the plumbing to turn off the water into the water heater.

I liked the fix which would essentially keep the water heater from flooding the basement.

Has anyone on this forum ever implemented such a scheme like this before?

How much would this cost - parts, labor?

-- Tom