I recently had someone take apart my heater to repair a water leak, since put back together I have no leaks but the temprature conroll is not working right. When I turn the dial on I hear a click (in the very cool position), the light comes on and the heater starts heating. The water temp is going up to 112, when I turn the dial back down nothing happens unless I turn it to where it clicks and it turns off. Would this be a stuck contactor?

It almost sounds as though the thermostat temperature sensor or the thermowell was not installed correctly when it was reassembled, since you have no thermostatic control what so ever. If you have the type of heater where you have to turn a knob at the heater housing, take the cover off and make sure the copper tube with the enlarged end is actually in one of the holes of the heater. If that is in place, then the bulb may have gotten kinked or a hole in it, rendering it bad and will need to have the thermostat replaced.

A stuck contactor would cause the unit to either not turn on at all, or not shut off at all, but yours does, when you turn the thermostat to it's coolest position.