Hi, One other thing it could be is an element that is failing. If an element has an electrical leak to ground, it basically doesnâ€™t stop heating, though it heats very slowly. Use a volt ohm meter to see if there is a problem by measuring between each element wire connection and the steel flange of the element. Power must be off and wires unhooked. Use the ohms times 1000 scale. If the element is good, the reading will be zero.
Ps, Any evidence of water or heat is burned smell around a thermostat points to it being damaged.