Don't know if you have fixed it yet but it sounds like you need a new thermostat. A local hardware store or home depot or lowes will have them. They even sell a kit with both thermostats and 2 elements so you can rebuild the whole thing. Might be more efficient too.
How Do I Fix My Electric Hot Water Heater State Courier 510? It Gets To Hot And Trips The High Temp Breaker.
My state courier electric water heater is not heating water.
Hot water heater is running and there is no hot water being distributed though out the house