I have a Rheem hot water heater model #62SV-40D, 40 gallon, dual thermostat. How to wire Thermostats?

The red wire from the lower calrod has become disconnected from the upper thermostat. Where does it go? The only place I can find to reconnect it is on the middle screw on the right side of the upper thermostat which also has a blue wire running to the upper calrod. Is this correct? Note: The upper thermostat has 4 screws on the left side and 3 on the right.I have a Rheem hot water heater model #62SV-40D, 40 gallon, dual thermostat. How to wire Thermostats?That's correct Tim. All double element water heaters are non-simultaneous units, in other words, the two elements are never on at the same time. The upper thermostat unit, controls the whole operation, in that it doesn't allow juice to the lower thermostat until the water in the upper half of the tank reaches the set temp. It then shuts down the top element and sends the juice to the lower element so it can heat. I carry this wiring diagram with me when I go on water heater service calls, so I can rewire new thermostats without having to guess where which wire goes. If you like to do your own repairs it would probably be a good idea for you to draw up a wiring schematic of the heater's set up for future reference.