Press and hold the "Set" button for three seconds and release when "01" is displayed.
Press the number pads to the desired frequency of days until regeneration. Press "Set" to confirm. Note that the unit is pre-set to regenerate (release the filtered water back into the drain and refill with water) every four days.
Press and hold "Set" until "Set Reg Time 02am" appears on the display. Press "Change" and then the number pads to set the desired time for regeneration.
Press "Set" to confirm the reset changes.