The thermometer probe should be IN the tank. So you can see what your temperature is on top of your substrate. The probe for the thermostat should be put between the bottom of the tank and the UTH. Since you already have the UTH stuck to the glass that might be hard to do now.
There are pictures in this thread that show how the thermostat probe should be.
http://ball-pythons.net/forums/showt...With-Pictures!