A water heater includes an electrical junction box that receives a voltage supply. The electrical junction box includes at least one cover plate for providing access to an internal portion of the water heater. The voltage supply passes through the at least one cover plate and connects to internal wiring of the water heater. A method for providing a control module on the water heater includes routing service wiring for providing the voltage supply to the water heater into an electrical connection portion of the control module, routing the internal wiring of the water heater into the electrical connection portion of the control module, and connecting the service wiring to the internal wiring of the water heater within the electrical connection portion of the control module.