Unscrew and detached front and back panels, and inside framework holding the sheet metal to the body, after removing the sheet metal, unscrew the box enclosing the control board, use needle nose pliers to unhook the sensor module from the board and place the new sensor into the spots where the old sensor was connected (thermostat area, hu
... Read moremidity Sensor, bucket switch, and control board). Close up the unit and your good to go.
Replaced the sensor and solved the problem. I had a lot of difficulty with the case holding the circuit board,etc because no easy way to service. Seemes they could have made it easier with a removable panel. I actually cut the wires and re-attached the thermister later after routing. Did not use the other parts of the wiring.