Are you saying you had to change the cord to fit the rec? 3 wire to 4 wire? Wall rec has 4 wires? If the cord from the appliance is changed to a 4 wire, you should remove the ground bonding strap at the terminal block on the back of the appliance. This should be a strap from the chassis to the 'nuetral' on he block. Remove it or bend it back away from the terminal block.
neutral and ground arent seperate all the way back to the panel
Will be if you do this. The whole purpose of the 4 wire thing. Supposed to reduce the possibility of electrocution if the cainet becomes energized. Not sure about the grounding to the water pipes in this situation. Maybe someone with more experience in electric will chime in. Seems I have heard of plumbers being injured/killed because of this practice. Not sure if the guy that told that knew what he was talking about.