Wiring/ Install help

Hi there. I purchased the Rachio 3 4 zone.
According to the sprinkler guy I’ve had come, I have 4 zones. I can confirm because when I do manual mode on my current controller, nothing happens for zone 5 & 6.

I have a rain sensor installed as well. Looking to not use that anymore and get rid of it. Any thoughts?

Please help me out with wiring because I’m very confused. I have a Rainbird ESP-6Si. Pictures below of the unit and the wiring.
Which one will I not plug in for the rain sensor?
I have 6 wires but only 4 zones. Does this seem right?
I just don’t want to find out when I get the Rachio 3 in the mail today that there’s not enough terminals for my current wires.

If anyone has a picture of their 4 zone Rachio 3, of the wires, I would like to confirm there will be enough terminals. Thank you

Please assist.

Much appreciated.

I have a 16 zone Rachio 3, so cannot provide a picture of 4 zones. However, I can hopefully help you. From the pictures, I do not see where you rain sensor is connected. I actually recommend at least getting the Rachio working without the rain sensor and it can always be hooked up later. I believe most people use the weather intelligence and not the rain sensor.

Since you would be using the supplied Rachio power supply, you only need to use the Common and zone 1-4 wires. I personally would say that many time people run more wires than needed for expansion purposes. In your case, it sounds like they ran a 7-conductor wire and hooked up 5 & 6 just to get them out of the way (unless those two wires are connection to something, but maybe do not know where and they are not working (somewhat unlikely)). I personally prefer to leave those wires the same length, but wrap the spare wires around the insulation of the bundle of wires. Does that help?



Thank you so much. That definitely makes a lot more sense. I looked up what the 7 conductor wire is, perhaps they just wanted to leave them not exposed.

I have a rain sensor outside, I took it off and tried running my current old system without it but nothing would turn on without it. Should try to wire that exposed wiring outside together? It’s two wires coming from a single wire (split) if that makes sense. 2-conductor wire.

I am assuming if the last 2 wires, 5 & 6 are wired, but nothing happens when I go to program 5 & 6, they just wanted them to not be exposed.
You’ve cleared up a lot of things and made this make more sense. My only concern is how that rain sensor was wired and if it’s connected to the common wire by any chance or power. There are no color indicators on them.

Thank you

On the rain sensor, where are the other ends of the wires connected? Are the spliced into the Common wire somewhere? The most comment way for rain sensors is they just break the connection of the common wire. Rain Bird calls one of theirs, “RSD Series Rain Shut Off”. Which sensor do you have? If yours is one of the most common ones, breaking the common wire when wet, you should be able to split the two wires together. I personally would try to answer the questions first just to make sure.

man_ESPsi.pdf (511.8 KB)

Hi @Thomas_Lerman
Please see the pictures below for what I know about this rain sensor.

I don’t think it is a rainbird brand one.

As you can see, I spliced the wires off because I wanted to get rid of it, however when I got rid of it I realized the sprinklers simply would not turn on without those wires connected to the sensor.

Second picture shows the wire going into the shed. My shed is a bit messy but when I looked in that corner, I could not find a wire leading in. I only found a power adapter for the existing controller. Perhaps that wiring for the rain sensor is spliced in somewhere?

As you can see in the other picture, there are only two wires running into the controller.
1 for power, the other 7-conductor wire we talked about.

So, you cannot see where the other sensor wires go or if they are spliced in somewhere?

Yes that is correct

Okay, this is what I would suggest. With the rain sensor disconnected: Disconnect one of your known working zone’s wire and common, measure the resistance (ohms) with a multimeter. Twist the two wires for the rain sensor together and measure the resistance again. If the first is 0 ohms or “OL” and somewhere between 20 & 60 ohms with the sensor wires twisted, then I would think that you can safely leave them twisted with the old controller running zones.

Will do, I’ll get a meter from one of my friends. Thank you so much!


All set!

Everything is all installed and good to go. Those two extra wires were duds.

The unit was not working without the rain sensor connected. I ended up testing by putting the wire together to itself, and it worked perfectly.
This rachio is such a huge upgrade. Thank you for your help

Glad to be of service. Please come back as you have questions, etc.