I recently took my old processor out of the basement it has been about 10 years since it was last used and I was excited to get my darkroom working again. When I filled it with water and tested it, everything seemed to work perfectly; LEDs lit up, the pump turned on, and the motor rotated and reversed direction perfectly. I checked the LED temperature display against a thermometer and it was spot on. I dialed in the set point at 30 C and waited to see if the heater still worked. 20 minutes later, the water had warmed from 20 C to 30 C. Great, I thought, but then the water temp just kept climbing it had reached 35 C when I finally gave up and turned the power off. I have since taken the cover off of the electronics to see if there is any fuse blown or any signs of corrosion on the circuit boards, but everything looks clean and neat. I checked all of the wires and made sure all the connections were good. I reassembled and retested but found the same problem the unit would heat but not hold the dialed in set point. After the water had heated up and I turned the dial down far enough, I could hear the heating element click off, and the temp would stop climbing, so the on-off circuit works. It just seems like the set point from the dials is not being read correctly. Is this a problem anyone has run across? If so, is it fixable? Thanks.