Only one wire per zone?

I am replacing an old orbit controller with the 2nd generation Rachio timer. The stations I am disconnecting on the Orbit timer have two wires wound together inserted into each zone. What is the best way to determine what single wire i should use to insert into the Rachio zones.

Looks like they’ve used an Ethernet cable (normally used for networking applications) for your irrigation. (I wonder what they did with the brown pairs)

I’m sure they’ve connected everything the same on the other side (2 wires for each “zone”), so technically you could stop using one wire (no matter which one) from each pair, but the cable was not intended for irrigation (thinner than normally needed) and two wires would cope better under these circumstances.

I would try keeping everything the same. Cut the old ends off, and strip the wires about 1/4 of an inch from the end. Make sure to twist them well before installing them into their respective terminals. Do a gentle tug test to make sure that they are sufficiently secure.


@rogmar54 - the comic answer is the wire that works. In all seriousness, do you have eight valves that have been doubled up to work on a four station Orbit controller? I would take the two wires out of each zone and put just one wire in and run that zone checking to see what is actually being watered. Then swap out the wire and re-run that zone to see if a different area is being watered. This way it can be determined if either wire will work, just one wire is needed or if there are two different zones that should be split up on the brand new Rachio installation. The four wires going into the COM terminal may need to be put into a wire nut to connect them together and then a single wire into the Rachio C port.

If either wire will work, then do as @Gene suggests. Also, if that is Ethernet cabling it is probably not designed to be direct buried or outside. Ethernet cabling should have an outer sheath and may say Cat 3, Cat 5, etc.

Thanks for your quick response.I only have four valves located at two different locations in valve boxes. I will make sure the com wires are joined and only one wire to the terminal at the rachio.
I don’t think the existing wire is ethernet wire.The wires that look brown are actually covered in brown paint from painting the wall.

Thanks Gene,
I would prefer to use only one wire per zone as you suggested. I don’t actually have brown wires at all. They were covered in wall paint by the previous owners.
Could I harm the Rachio by using two wires at each zone?

No, the individual wires are smaller than irrigation wire which is commonly used. Two, or even 4, Ethernet cables, twisted together, should be within acceptable range that terminals can support.

This is a fascinating thread. You guys are amazing.


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@Franz -

Thanks. I may know a lot about a little or is it a little about a lot, I forgot.

@rogmar54 - @Gene is referring to the color scheme for wiring in TIA-568 - as there is a solid brown and white with brown stripe, to go with the blue, orange and green paired wires. No issue on the missing brown pair or confusion with the paint.

Without a reference scale, I can’t tell if the wire is the standard size for network cable or not. The Rachio unit can handle two wires (of the right size) in each port and there are two C(ommon) ports so you could split the four COM(mon) wire into two pairs. It looks like there may have been two sets of wires used to wire up the system as there are two sets of green, blue and orange wires. If the sprinkler valves are accessible via a valve box, one can check the other end of the wiring to see if the wires are paired up there too. If the plan is to place both wires in one Rachio port, I would do as Gene suggested and trim them up and get a new tight twist. If the plan is to place only one wire in a Rachio port, then one could wire nut the existing two wires together with new pig tail to go into the Rachio port.


Guessing from the photo this looks like two runs of 24/3 telephone wire which would explain the lack of any brown pairs you’d see in in a /4 bundle.

There is something weird going on with zone 2. It sort of looks like the solid orange wire just ends and the copper is wrapped around the orange-white wire. Does it actually continue around the back and into the terminal?

If you truly only have 4 zones I’d feel much better by re-wiring all of it with larger gauge wires.


Phone 3 pair wire makes sense, good observation.

I think that zone 2 solid orange wire was stripped too far back, exposing bare copper wire from where you see Orange wire end (hidden by the stripped one).

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If you end up using only one wire (say orange vs orange/white) I would recommend that you just cut the wire you do not use (ex. orange/white) at the end, tape it up with electrical tape and label as the appropriate zone. That way if you every have a wiring issue you have a backup.

Since there are two wires per terminal, most likely 24AWG, then you need both for voltage drop reasons. A single 24 AWG wire may be too resistive and have a higher drop. Two 24 AWG wires are roughly equivalent to a single 20 AWG wire so drop becomes less.