It was stuck open, decided, hey I'll replace it, cheap, easy, what could go wrong.
Second day into my thermostat project here is my progress:
here is my next step:
Time for the drill, lets hope I don't break the bit/extractor and have to pull my head off and get it machined out.
Unfortunately it bottomed out (wrong bolt apparently) only it bottomed out at 90 psi using the air tools. But It didn't break through the back so I'm still hoping it can be removed without drilling all the way through. I'm not confident I'll be able to tap the hole straight if that's the case.
Luckily it's only 97 out today =p
Edit - oh that notch you see is the failed attempt at removing it with a screw driver, it just breaks the bolt more. Didn't think going further into the housing was a good idea.
Edit - 2 - Broke extractor off... awesome. any ideas? bought the best bit I could find to attempt drilling into it, but it's not working, even at full speed on my 1/2" drill it just annihilates the bit after a while. I was honestly surprised the bit didn't snap.