Water heater controls operate off a bi metal switch located in the back of the thermometer. Power is sent to the top left terminal and when the thermostat calls for heat power it is sent to the lower left terminal and the upper element energizes. When power is satisfied it is transferred to the lower elements. Controls are UL and C-UL Recognized and CSA Certified.
Note: Product availability is real-time basis and adjusted continuously. The product will be reserved for you when you complete your order.