THANK YOU!!!!! For once someone comes on here with heating problems and DIDN'T put the snake in it yet. Most people come on here asking for advice with heating and the poor snake is in the cage burning up.

If i were you, i would return that rheostat and pick up a Ranco Thermostat either wired for around $80 or un-wired for about $50. I have the same issue with my Zoo Med rheostat, it's on the lowest setting and still gets the pad up to 112 degrees. So i just stick the appropriate amount of air space between the tank and UTH to get the right temperature.

Rheostats vary so much in temperature, it's impossible to get them to be accurate for any period of time. Also if you have 2 snakes and 2 tanks to control, it would be worth the extra money. Plus those Zoo Med Rheostats are like $22 at petsmart, so i would spend the extra and get a good Ranco or Johnson Thermostat.