Originally posted by d2bernhard
Old one was stuck in there, but appeared to be closed from the top at stone cold. Had to pull out with pliers and broke on the way out so I cannot know for sure if it was broken.
This happened to me the first time I changed out a thermostat. Mangled the thing pretty good. The next time, I thought to dig out the o-ring with a pick, and the thermostat popped right out with no fuss.