I have an 40 gal us craftsmaster electric water heater. My friend and I have been replacing parts periodically and are about to give up. The only odd thing I noticed is the wiring of the upper thermostat. The two middle contacts of four, on the left side, have no wires attached to them. The wiring diagram shows they should be connected, but the manual does not define with what kind of wire. I already tried contacting the home website ,and I am not the original owner of the house or the water heater.