Well I just thought about this.. Don't mean to argue with ya Bio, but he showed me the difference between the normal T-Stat and the FailSafe T-Stat. The normal one was just normal..
http://tooldesk.com/blog/wp-content/...thermostat.jpg
The Failsafe T-Stat:
http://www.wilsonmanifolds.com/shop/...thermostat.jpg
Those bronze added thingy's help it stay open if failed. I don't know if they are drilled or not.