On the side of the receptacle, in between the two brass screws, there is a small piece of metal that connects the plates that the two screws are screwed into. This tab needs to be broken off with pliers in order to isolate the two receptacles. Bend it back and forth a few times and it will break off. These two screws should be where the cooling hot and heating hot connections are made correct?
You will need to determine how much cooling undershoot and heating overshoot occurs in your fermentation setup and set the controller differential above the larger of the two. You can get the undershoot and overshoot to their minimum by attaching the probe, under insulation, to the fermentation carboy or bucket. The thermal mass of the fermenting beer helps mitigate this issue.