Abstract: A data protection and recovery system for an energy controller for a water heater is disclosed. The energy controller is a microprocessor based system which includes a central processing unit, volatile and non-volatile memories, and a clock. It functions to energize the water heater only during a certain period of the day. During normal operation of the system, the system uses the volatile memory as a workspace, and normally copies data in the volatile memory to the non-volatile memory. The system senses electrical disturbances, such as power surges, and prevents the writing of any data to the non-volatile memory components during the electrical disturbance. After the electrical disturbance subsides, the system checks the integrity of the data written to the volatile memory, and if it was not corrupted by the electrical disturbance, the data is then written to the non-volatile memory.

Abstract: The disclosed system reduces power use during peak loads by automatically shifting the energization of the water heater to periods of off-peak power use. An energy controller maintains a calendar clock and controls the application of power to an electric water heater so that only on non-holiday weekdays, power to the water heater is interrupted during those periods of the day which have been predetermined to be the periods of peak power usage. The consumer whose water heater is controlled in accordance with the system is provided with an override button so that once a day the consumer may institute an override period to energize his water heater regardless of the peak power usage schedule. The energy controller contains in a microprocessor memory status data which includes the calendar time, a listing of the holidays, the schedule of peak power usage and the override interval.