New here but I wanted to share how I was able to connect a Hunter Rain Clik Sensor to my new Rachio 3. This is the Costco 12 zone unit. I kept the Hunter Rain Clik Sensor from the previous setup.
YMMV…This worked for me: First, the wiring diagram offered by Rachio for connecting the Hunter Rain Clik Sensor to the Rachio 3 is correct. Begin by twisting the white wire from the sensor together with one of the yellow wires from the sensor - it appears that it doesn’t matter which yellow wire you choose. Then follow the Rachio diagram: White/Yellow from sensor to VAC(-); the other Yellow from sensor to VAC(+); and Blue from the sensor to S1. The Orange wire from the sensor is not used.
I had it set up this way for a couple of days and it still wouldn’t work…Here’s what I did that seemed to make a difference:
Go into Controller Settings on the Rachio app. On mine, under Advanced Wiring (M Terminal), Master Valve was checked on by default. I turned that off because I don’t have a master valve.
In messing around with this connection it’s easy to have ended up checking both the S1 and S2 boxes under Accessories > Sensors. Go back and make sure you’ve checked only the S1 if you’ve wired it like I did.
Additionally: I sprayed some water up onto the sensor from a garden hose. This activated the sensor and I was able to confirm this by seeing Rain Sensor Activated in the history list. On the Hunter Rain Clik sensor, you can press the Bypass button on the main unit (mounted by your Rachio), and do a history check. In Bypass mode, it should indicate Rain Sensor Deacitivated. Press it again to turn off the Bypass and the history check should indicate Activated. This is a quick check of the overall circuit, and does not rule out testing via the little button on the outside sensor itself when the sensor is dry.
This may or may not help you. I wanted to give a little back to the forum because I was able to learn from some other posts and topics here, and it seemed that this issue was not always followed to resolution.