Wiring from a Hunter Pro with new rain sensor to Rachio 3

Want to purchase a Rachio 3 and install it myself - I have included a pic of my current Hunter Pro with newer rain sensor - is it possible to use the Rachio 3, still use the rain sensor and if so, what would be the wiring configuration I would use…many thanks for the help

@denpo , do you have a master valve? If so, might need a little more info on that. Other than that you can use the rain sensor w/ the Rachio 3. The two yellow wires would go to 24vac one in each and one of the sensor wires would go in Sen on Rachio the other would go to -24vac. image in this pic your yellow=red and your white and blue=yellow and white.
The rest of the controller should go to the corresponding C, M, and Station #s

how would I know if I have a master valve? Where would I check ?

@denpo - based on the wiring in the Hunter Pro there is either a pump start relay for use with a well or a master valve (see the terminal with the P/MV marking). If one doesn’t have a pump, then by elimination it is a master valve.

A master valve is just like every other valve in the irrigation system, however this valve is before all the other valves. The use of a master valve helps prevent water leaks from a leaky valve or broken line.

I don’t think there is a need for additional information, one will just need to enable the master valve option in the Rachio app. And the wiring is just like @gaustin mentioned. You should be good to go and a Rachio can replace the Hunter Pro.

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Thanks… Do not have a well so it must be a master valve… so where does the black MV wire go in the Rachio… in the M slot?

And what about the green and white “com” wires?

@denpo - Yep, the black wire in the Hunter P/MV terminal goes to the M terminal in the Rachio and the green and white COM wires can each have there very own C terminal in the Rachio.


thanks much - I have ordered the Rachio 3 - feel confident that I will be able to install, but will reach out if I run into an issue

one last thought - is there a way to test the rain sensor once I have it installed to ensure functionality?

thanks again for the help!

@denpo - most rain sensors have a manual test switch. One can always soak the rain sensor by pouring water on it to see if it still works. With Rachio, the rain sensor is a belt and suspenders approach to catch the local unforecasted rain shower.


Sorry another question - as I read up prior to installing - for the sensor wires, one goes in S1, does the other go to 24VAC +or-…the rain sensor I have is wireless

thanks again

It goes to -24VAC.

@denpo - What @gaustin said. Here is a wiring diagram for the Hunter wireless rain sensor ->


I have the same sensor. Didn’t have any luck getting it to work with the Rachio 3. Did everything that was suggested. I rely on the weather sensor now