Replaced Hunter Pro-C with Rachio 3 16 Zone

I replaced my Hunter Pro-C 12 zone sprinkler controller with Rachio 3 16 zone controller. It was watering alright before replacement. But after replacement, no watering occurs. Tried zone testing after adding controller, quick run and even manual testing at the controller without using the app. None of them result in any watering at all, My Hunter Pro-C had 11 zones wires and one COM wire. In Rachio, I connected the COM wire to the leftmost C and the the 11 zone wires to zones 1-11 leaving 5 zones unused. Unable to figure why it is not working. I don’t have any special equipment such as sensors or flow meters. The controller is installed in my garage. Here is my wiring:

It does look like you have it wired correctly. Maybe try gently pulling on the common wire and make sure that it is seated properly. You can also try it in any of the other C terminals.

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There is a white wire, that is lost along the way (seems to have dissipated into a screw mounting hole). Do you know the original purpose of that wire? I would try to connect it to commons as well, since white is the most widely used color for common line.

In case you have a picture of your previous setup, it would be useful to debug the setup and see what went wrong.



My Hunter Pro-C wiring has a white wire but it is not about zones or COM. It is connected to AC2 (of the group GND, AC-1, AC-2) along with the AC-2 wire coming from power connector (which has three wires connecting to GND, AC-1 & AC-2). I guess none of these wires are relevant to Rachio 3 since it uses a AC-to-DC power connector. I have pictures my Hunter Pro-C wiring captured in WhatsApp but they are not uploadable to this support site. I may need convert them first. I will try that.

It would also be helpful to take a photo of your valve box. Not every wire connected to AC terminals on your old controller was a power source wire, the white wire is likely still common, just hardwired to a “negative” leg of the power supply.

I would simply hook it up to one of the common terminals and trying to run a program. Chances of a live voltage being supplied by the white wire are essentially zero, especially if all three of the old supply wires are accounted for.


Definitely didn’t have a wire hooked up to the P/MV terminal in your Hunter Pro-C?
I migrated from a Pro-C with a master valve + 10 zones. My Pro-C also had two wires going to COM, one to GND, and two apiece to AC1 and AC2, plus a wireless rain sensor on the two SEN terminals.


Here is the wiring for my Hunter Pro-C PCC Series 12 zone controller:

The first picture is about power & sensor connections and second picture is about COM, Master & Zones. I don’t seem to have a P/MV connector the way my sprinkler system is setup. In the Rachio app I tried with both the M-Terminal ON & OFF. I have only one COM/C wire.

@Gene, is correct the white wire needs to go to a C terminal in the new Rachio controller.

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In my Hunter Pro-C I had a Smart Remote Connector with three wires connecting to the AC1, AC2 & REM connectors for its power supply.The white wire is among them connecting to AC2. There is no white wire coming from the non-power related connections in my setup.

I think the issue is the color balance of the original photo. The white wire looked brown, whereas the original brown wire remained unused at the bottom left.


@prvishnu - that looks wired almost correctly - see Gene’s comment…

The thin red, white and blue wires on the Hunter go to a remote control device (I believe) and can be abandoned when going to the Rachio.

When attempting to water, what do the lights show? Do the light up the zone that should be watering?

Can one manually open the valve for a zone (using the bleed screw) to see that water comes out of that zone?

Does one have access to an ohm meter to test resistivity/connectivity down a zone line and back up the common wire?

@Gene - dang you’re good! I’m on board with you and switching the wires!


Hi Gene:

Thanks a lot! Yes, that hidden wire - somewhat brown looking wire - is supposed to be the white wire. And the one I connected to C is actually my 12th zone wire which is not active in the sprinkler system and that is why it is not numbered. After I connected the white wire to C, it worked. I am now getting water. Thanks again.


Hi DLane:

Thanks for your comments and of others as well. You were right about the red, white & blue wires corresponding to remote control device. You seconding Gene’s observation also prompted me to look at it more seriously. In the end, my problem is resolved. Great community!