Couple of quick questions - Switching from a Rainbird to the newest Rachio. My experience with these hookups goes no further than switching to a Nest thermostat, so please forgive my stupidity in some of these questions:

(1) The 24VAC and GND from the Rainbird do not need to be connected, correct? Any need to cap these wires for protection if just leaving them unused?

(2) I have a small looped yellow wire connecting two terminals under SENS on the Rainbird. Which S terminals should I connect to on the Rachio?

(3) I also have two separate common wires on the Rainbird going to the COM terminal. Ok to connect these to any C terminal on the Rachio or do they need to connect to the same one?


@jeffreytneal - No worries on the questions, that’s what this community board is for. The only stupid questions are the ones that aren’t asked.

  1. Correct. You may be able to trace the 24 VAC wires back to a plug in transformer. If so, unplug that transformer so you won’t have that vampire sucking electricity. GND is ground, should be no current and you can abandon in place.

  2. I don’t think you need to do anything with the yellow wires on the SENS terminals. I take it that there is not a rain sensor connected in the current setup?

  3. There are two C(ommon) terminals on the Rachio. These wires can go in either terminal individually or combined.



@DLane - Thanks for the help!

(1) Wow…that was just dumb on my part - thought the wire went behind the wall, but traced right back to plug…DOH!

(2) No rain sensor currently set up, but may consider in the future. Just left yellow wire off and functioning fine.

(3) Great.

Yeah, took 30 minutes, and hooked it up and we’re up and running - Thanks for all the help.