Deleting a Rachio Controller
If you already have one or more device(s) associated with your Rachio account, and you need to delete a device manually, you can do so through the Device Settings option found on your app Homepage. Simply ensure the device that you want to delete shows a the very top, then select Device Settings > Delete Device > check the box > press OK . ( see images, below )
NOTE: You will be presented with a warning message to make sure that you really want to delete your device. What you delete cannot be undone so make be sure that you are certain before you delete an device.