Water Heaters - Energy Cut Off Control (ECO)
The water heater is equipped with a combination thermostat and high limit Energy-Cut-Off control (ECO) that is located above the heating element in contact with the tank surface. If for any reason the water temperature becomes excessively high, the high limit control (ECO) breaks the power circuit to the heating element. Once the control opens, it must be reset manually. Resetting of the high limit control should only be done by a qualified service technician.
Caution: The cause of the high temperature condition must be investigated by a qualified service technician and corrective action must be taken before placing the water heater in service again.