The heat pad is way too hot; are you using a thermostat to regulate the heat? From what I read it doesn't sound like it and you're risking your snake getting burned or worse. Turn it off until you get one.
Your snake needs two hides; one on the cool side and one on the warm side so it can choose which one it needs to go to. Our snakes will often move from one to the other during the day.
None of our snakes soak; the only time one did was the pied shortly after we brought him home. Turns out he had mites
For now turn off the under tank heat pad until you get a thermostat to regulate the heat.