Current to Peltier seems to be reversed

Hi! I have a Mastercycler Gradient 5334. I just replaced the block and whenever I try to run a cycle it overheats. I have checked the current to the Peltier and it is +/- 5A, which is correct according the the manual. However, when when I am trying to calculate the Peltier current limitation (PW), when I set the PW to -180, I get a positive voltage of 5A and at a PW of 180 I get -5A. According to the manual, it should be opposite. When I set the PW to -180, I should be getting a current of -5A and vice versa. Does anyone have any suggestions? I'm at a loss for what to do next. Thanks!!