Sounds a though the thermostat may be faulty and not turning off the power to the heater when the water temperature has reached its upper limit or cut off point.
Hi @d2icsw2ehjpsdob,
What is the model number of the water heater?
Sounds a though the thermostat may be faulty and not turning off the power to the heater when the water temperature has reached its upper limit or cut off point.