Hunter SRC to Rachio 3 - Wiring

Hey Guys, I just got a new Rachio 3, 8 zone system.

I have gone through a few posts and I understand the C from Hunter Plus goes to any C (Common on Rachio)

I have two wires on the RS (which I assume is Rain Sensor)

Where do those go in the Rachio 3?

I took a look at the manual below. It indicates:

  1. Route the wires from the rain sensor up through the same opening used for valve wiring.
  2. Connect one rain sensor wire to the RS terminal and the other to the C terminal.
  3. Connect the valve common from the field to the RS terminal.
    Note: If a pump relay is being used, the pump relay common must also be connected to the RS terminal.

So, it would appear one of the RS wires is a valve common. The trick might be figuring out which is the valve common.

I also included a link below to checking compatibility and hooking up of the rain sensor.

You will not want to hook 24 VAC wires to the Rachio, rather use the Rachio supplied transformer and its connector.

I hope this helps.

Can you please explain 2 and 3 to me? I am assuming this is part of the hunter terminal technical manual?

In the Rachio system, I have c which is common. I have city water so there is no master pump

If I want to bypass rain sensor, then common sense would make me just cap those wires isn’t it?

As stated in the “Rain Sensors FAQ” article listed above, you really do not need to use a rain sensor if you do not want to. Rachio uses local weather stations (I suppose depending where you are) to understand the weather, more than just the precipitation.

The numbered list that I provided was in the Hunter owner’s manual in the first link that I included (see page 8). My interpretation is that when you are using an RS, Hunter has that hooked up to RS & C and you move the valve’s C to RS. Did that make sense? In other words, RS will have the sensor & valve C and C will have the other part of the sensor. I am not sure why that is.

So, if you do not use the RS, leave it disconnected and you will cap them when you are done. You will just have to figure out which of the wires is the actual valve C. If you have a multimeter, you can test the ohms between valve 1 and go through each of the wires (starting with the ones on RS and one at a time). You should read between 20 & 60 ohms if it is a valve. Otherwise, you probably will get 0 ohms if going from zone 1 to the actual sense.

Hi Thomas

Perhaps this is the solution

If you look at my photographs,

Wires Marked 1, 2 and 3 will have to go to S1, -24V and C. I just have to do a trial and error to determine what goes where

I wish my contractor had used colored wires. Would have made it much easier.

This post also is similar

I definitely would figure out which of 1, 2, or 3 is the valve C wire first. If I read it correctly, it seems like it should be 1 or 2. Then, you will know which are the RS wires and referring to that first “Rain Sensors FAQ” (after knowing the model of the RS), that should be relatively easy to figure out. Are we saying the same thing?

1 Like

@s_ranga108, I believe the two wires on RS are your rain sensor, Rachio doesn’t really need this hooked up but if you want to I believe one wire goes to S1 and the other goes -24VAC(make sure you enable the proper sensor in the app). The lone common goes to any C terminal in the Rachio and the red station wires go to corresponding stations on Rachio.

If original was wired correctly, the true common is one of the two wires connected to RS terminal. Rain sensor simply shorts that terminal to Common while dry. Rain Sensor terminal is an input, if controller sees voltage on that terminal, that means Rain sensor has disconnected common from C terminal, ideally due to being wet.

1 Like