DO NOT 'drop' the stat in, as it needs to be off the bottom of the pot. Then put a cooking thermometer in the water (again, off the bottom of the pot). Then check it that way.
Another thing is to drill 2-3 small 1/8" holes around the edge of the stat so water (and any trapped air) can circulate out.
Have a friend that had heating issues. Ended up being a small air pocket around the temp sensor and he had to 'leak' it out to get rid of it.
Hey Justin, didn't you post that EXACT SAME THING like months ago ??

maybe someone else ?