Under the hot side, the snake needs to be able to choose between being hot or being cool. Placement in the center won't give them much choice
My opinion is that Ranco is garbage. I've had several that quit working after only a couple of years often to the deterament of my snakes. Once it caused a rack to run it's heat tape at full power and I lost several animals. I've had good success with the very similar Johnson thermostats but I currently prefer the Vivarium Electronics brand http://www.reptilebasics.com/thermostats Or the Helix systems http://helixcontrols.com/2. I've read here that Ranco makes superior controllers, this is what I am missing. Before I actually place the order, is this the right thing? It is on sale for over half off on Amazon! (56% off!)
I know some people don't trust them but I've also had good luck with the hydrofarm themostats as well. http://www.amazon.com/Hydrofarm-MTPR...gy_misc_text_y
Just the probe. You really don't want any electronics inside the cage where they could get soaked by an overturned waterbowl.3. I have also read on this forums that thermoSTAT probe goes on the pad outside the bin, and thermoMETER goes inside and above the mat. Does the device itself go inside, or just the one probe? Please explain how this should go, I don't want to mess up such an important step. D: