recommendations for automatic shutoff valves for water heaters?

Any recommendations for ASOV for water heaters? I have done a search and many reviews are iffy. Many valves seem to not work after 6 months or so. WOW! At $120 plus that would royally tick me off.
Replies
How
would you know if it didn't work until it was too late?
Yea, quite a scam ... aaah?
Well, the reviews I have read say they have done tests where they wet teh sensor and nothign happens, or teh transformer failed ... don't recall how they discovered that and a transfomrer failing has to be realy rare. Anyway, do most people just not bother with a ASOV? I guess so, but it sure seems like a great idea. I have always had a heater in an unfinished basemetn, so never really cared or gave it much thought. I a buildign with a heater on teh main floor and figure I would hate to have a mess.
Thanks for teh recommendation by the way, LOL.
They make cheap and readily available aluminum drain pans for WH's. Or, if you wanted something more substantial, you could set your WH on a Flood Saver pan (usually made for washing machines) or make your own waterproof pan.
Do those pans need a drain?
Do the pans need a drain? Or are they just designed for small leaks and then you can get a cheap alarm sensor?
small sump near water heater
float in sump with string to trip latch on platfom a few ft up
brick on platform.
string around brick to handle of ball valve mounted on 45 deg angle inlet pipe
foolproof, works every time, never wears out
Add a bowling ball on a 2 " platform a few feed up with another string, now you have an emergency earthquake shutoff also.
annual maintenance
When possible, we always prefer to install a water heater in an aluminum drain pan with a gravity drain pipe. We have used scores of the FloodMaster brand of automatic valves with good results. Just like most mechanical devices, they require annual ( or semi annual ) inspection & testing.
You can increase a water heaters life significantly with proper installation & maintenance including : install a pressure reducing valve, thermal expansion tank, and dielectric couplings, remove & inspect the anode rod (s) yearly, drain & flush the water heater at least once a year, and exercise the relief valve yearly..............