OK, so I did the pan of water test to the one thermostat I had lying around hoping it was good (brand is Vernet Calorstat, French). At 180F, which is a little over 80C, the rubber seal in the center was only open a couple (maybe 4 max) millimeters around the edges. I can't believe that this is as far as it goes. Is this a bad thermostat? Does anyone know what the best brand of thermostat is, because I have had no luck with this brand or the last Behr I got.