I have bought three hot water heater thermostats so far! First one broke cuz I'm an idiot, second cuz someone else is an idiot, and the third because, well, I don't know! Al the parts are fine, the rivets were drilled out with precision, the holes went through right where they were supposed to, but it's not working! The light will just stay on, instead of turning off at the desired temperature. Does anyone have any ideas? Like, should the casing be on REALLY tight or somethign? Ill put up pics in a minute.