Changing the controller from weathermatic

I am planning to switch to Rachio Controller from Weathermatic and wanted to do it myself. Thought it was going to be easy and 10 mins job, but I need some answers and confirmation from you guys. I currently have Weathermatic and a rain sensor. After reading some, decided to keep the rain sensor and replace the controller. I have added the picture of my current controller for clarity.

  1. I have 9 zones and the switching the wires for the corresponding zone should not be a problem.
  2. I thought the white wire would go directly on the COM slot however the wiring is different currently. Instead the white wire is connected to white wire from the black bracket wire ( which comes from the rain sensor) and the yellow wire is in COM slot.
  3. The red wires from the black bracket will go to the 124 VAC + and - terminals.

Should I just do as it is currently and place the yellow wire in the COM slot and the red wires in the 24 VAC + and - slot

should I connect white wire from the bottom bundle of the wires into the COM slot
then the yellow wire from the black bracket to the S1 or s2 slot. White wire from the black bracket into the 24 VAC - slot
the red wires go the two 24 VAC slot

I hope the picture makes it easier to understand it

What kind of rain sensor do you have? If Weathermatic, I am not sure if that is supported or not. Here is a page that talks about which are supported and then links for how to hook them up. Because of the hyper-local weather forecasting that Rachio uses, most actually find that they do not need a rain sensor. The problem with rain sensors is that they usually just prevent the sprinklers from running no matter how much rain they get. The way the rain sensors generally work is that if it senses rain, it cuts off the ground to all zones, so they think they ran but really do not. That is why you are seeing what I think you are describing. Rachio does it differently so it actually postpones the watering in many circumstances (if I understand it correctly and depending on how much rain it gets according the weather reports, etc. . . . I do not have a sensor).

I would start off with making sure all of your zones are working to begin with and maybe even map them out at the same time. I would suggest after seeing what rain sensor you have and see how it hooks up, bring over the zones as if the sensor does not exist. Maybe even disconnect the rain sensor and hooking the ground wires to common to make sure everything still works. The wiring on Rachio will be the zone wires straight over as you said. The ground (sounds like they are white) to the C terminals (they all connected together so would suggest one wire per terminal). This part will be the same whether you end up connecting the rain sensor or not. You can test it out this way and then decide about the sensor after getting to know Rachio, app, etc.

Did I cover all your questions?

Thanks for the reply. My rain sensor is Hydro Rain HRC 100. I don’t see it in the supported rain sensor list however seems like it has worked with other members of the community.
I have it already installed and working, hence I decided why not continue using it.
I guess my questions is about the wiring to make sure it works.
My research here in this community tells me the way it should be done as below. and I guess I just wanted someone confirmation that I am doing it right

Rain sensor’s wire to be connected to rachio 3:
Red 1 to 24 VAC -
Red 2 to 24 VAC +
White to 24 VAC -
yellow to S1
Green --leave it as it is ( not connected

Wires from the white pipe
White to COM
remaining wires 1-9 to corresponding zones 1 -9 ( I already know the zones)

I was confused by the way this hydro rain sensor was connected in this controller as the 2 white wires are connected and the yellow goes to COM. I am assuming whoever did this did it this way to ensure the controller is switched off when it rains.

I do not have one of those sensors, but it sounds & looks correct according to Connecting Hydro-Rain HRC-100 Wireless Rain Sensor to Gen3 - Accessories & Sensors / Rain Sensors - Rachio Community.

That is the common way to use a rain sensor with most controllers . . . when it rains, cut off the common wires to all zones. This makes it work for most controllers even though most controllers especially “dumb” controller were not designed for sensors. I like the way Rachio does it, it seems like they thought about it during their design. Remember to set up the rain sensor on S1 within the app.