Your unit is equipped with a battery backup system. In the event of a power outage for less than 24 hours, the control valve will remember all settings and time of day. For an outage over 24 hours, the only item that needs to be reset is the time of day, which will flash when a reset is required. All other settings are permanently stored in the nonvolatile memory.
FOR TOTALCARE SERIES CONDITIONERS:
Time of day will not need to be reset. The system will recognize resumption of power and will switch back.