Well it looks like this was a mistake on my part so I'm here to own up to it.

I could have swore I read something recently or talking with a vendor about a T-Stat that would fail open. But, after further research it seems to still fall into the gimmick marketing you mentioned. I did some poking around and can't find one that will actually fail open (Meaning, if it fails in a closed position, the thermostat will actually "override" so to speak and push it back open) The only thing I continued to find was the "lock open" at X temp.

Actually also found this from Stant as well.

Does Stant have a fail safe thermostat?
All thermostats will fail in either a closed or open position; there is no such thing as a thermostat that will fail in a “safe” position. Although some brands may claim a thermostat fails in a safe position, it simply locks itself open while it is in a full stroke open position. It will not spring open if it fails in a closed position.

By the way, I read my previous post again. Definitely had way to much going on at work when typing that. So many grammatical errors. Hah. Good call out though. I'll stop posting now and go have a beer...err many rather.

 

Yep, there's some good info over at the Stant web site......and I've been lucky using there stats for almost 50 years. Good stuff and a OEM supplier as well.