First things first.

Follow the advice of previous posters with regard to scale issue, and placement of the probe outside the tank, between The uth and tank

Next-he needs a warm spot (not necessarily basking) between 88-92, and a cool spot around 80. He needs these temps 24/7, so if you are shutting off the 25w lamp at night, he does not have an adequate cool side. Before I switched to tubs, I had a 50w red heat lamp (snakes cannot see this light, so it can be left on all the time), and a uth set at 95. A few degrees are lost between uth and inside tank. This allows the snake to thermo-regulate as needed.

Finally, "not hiding" is a bit vague. For some, burrowing under the substrate/newspaper is good enough. If he is not doing that, it means he cannot find the right temp, and he is forced to choose between good temp, and security of hide. This of course stresses the snake, and if he is dealing with other issues as he is, it will be more difficult for him.

Get your husbandry right, and it will really help him battle his scale issue.