Replacing Discontinued Rainbird


Greetings all! Just received my new Rachio 3 this week (yay!) and I’m looking at the wiring on the previous timer that the old owner installed. I think it’s a Rainbird Model RPI-800-M based on the sticker inside the cover. I’m a little stuck as to how the wiring is labeled and what matches the Rachio however. Here’s the “main” wiring of the old timer, I don’t see a Ground in the Rachio box, and not sure if the old AC1 & AC2 each go to a “C” connecter in the Rachio3 or if only one is necessary. I’m also assuming the 2 “SEN” connectors on the old timer would go to the S1 & S2 connections on the Rachio.

Thanks for any input!


@FubarGuy - ignore the Ground, AC1 and AC2 connections from the Rainbird, they are not needed in the Rachio as they are supplied by the Rachio power supply that plugs into the device.

For the SEN(sor) connections in the Rainbird, I’d put one in the Rachio S1 and the other in the SC. I’m assuming that is for a rain sensor.

Welcome to the community (and thanks for the link to the picture).


Awesome, thanks! I’ll cap off those 3 wires, and I agree on the Sensor(s) as I know there’s one rain sensor on the upper roof gutter someplace, but I suspect it’s faulty. My understanding is that the Rachio will partially determine running cycles by the localized weather, and at some point I’ll get up to replace that sensor too.

I’m going back in! :smiley:


@FubarGuy - track those AC1, AC2 and Gnd wires back to their source as that transformer will be a vampire sucking electricity all the time. Not much, but still. And I might start off with not hooking the rain sensor up if you think it is faulty as it will just give you grief.


Ok, I’ll see if I can trace those ACs. Previous owner did some “interesting” things I’m finding out.


Hmmmm, just found a set of wires marked “COM” that appears to be 3 braided together. Can’t see where they run to, as all of these go through a conduit under the old timer box, then up & out - I’m guessing to an external buried box. Guess I can bypass those as well as they don’t appear to have any matched on the Rachio unit. Oof.


@FubarGuy - those wires will go in the Rachio C(ommon) terminal. I believe they’re needed! If you have a 16 port Rachio there should be four C terminals and an 8 port will have two C terminals. I might suggest creating a pig tail and wire nutting the three common wires and the pig tail together and inserting the pig tail into a C terminal.


Eh, I think we’re done for tonight! My 30 minute install just got to be more than I was ready for, I’ll tackle it again later this week. (At least I didn’t cut the old AC power cord like I was inclined to, since it’s hardwired into the Rainbird timer box!) :stuck_out_tongue:

Thanks for all your help, have a great night.