Sorry if this question is wordy and redundant. I was not able to find a similar issue on the other posts. I have used the Rachio 1 product in our old house and loved it. I decided to leave behind for the new owner and have purchased the Rachio 3. Unlike the last install, this one is a bit tricky. In the attached photo, it appears that the existing Rain Bird 24-LX Plus has 2 wires into most of the zones. Is this as simple as just twisting them together for the Rachio 3?
Considering that there are enough zones on the old controller, I would recommend hooking up top row of wires to unused zones 13 through 24. Prior to switching over try running every zone and note if any are unused. We had other users with similar controllers to yours. Seems that abundance of terminals is an easy way to terminate any unused zones (in case more zones are coming in than are actually needed).
You are better off identifying the wires that are actually needed and leaving unused wires disconnected. In case you do with to proceed with twist and hookup method, than I recommend you use a wire nuts and not force a thick twisted pair into the Rachio’s terminals.
Above topic may provide some guidance as to what you are facing. Let us know if you run into any issues
Welcome to the community, enjoy your updated Rachio
@joew - what @Gene said - only hook up the wires that are necessary. Another option if one has access to an ohm meter is to test the resistivity between the wire pair and then between each wire and the common to determine the wires actually in use. One could also check a valve box to see if more than one wire is connected to the solenoid and to confirm the common wire.