Master, Zone and Sub-Zones

Hi Rachios,

I’m new to Rachio, and to irrigation. My house did not include an underground irrigation system, and before investing in one I’m doing it all with above-ground valves and sprinklers, connected with garden hoses.

Please consider my desired setup in the following diagram: .

I purchased a Rachio Gen2 16 Zone controller, and have setup most of the system per the diagram, but then I hit a wall with my plan, realizing that I don’t know how to program the Rachio controller to operate zones 4 & 5: for zone 4 I would need to open valves M+3+4, and for zone 5 I would need to open valves M+3+5.
I could even do without the Master Valve if it helps, but it looks like the main issue is not with it, but with using valves 4,5 as sub-zones of zone 3, and making sure they open together.
I understand it could probably done with electronics, using voltage from both zones 4,5 to operate a relay to start zone 3, but it sounds like too much work to get something simple done, if the controller is flexible enough, or allows low-level control.
I’m a programmer, and I don’t mind even skipping the app and controlling the zones directly via API if that’s the best (or only) way to go. I could imagine getting an IFTTT even that zone 4 is opening, and react by programmatically opening zone 3 to feed it.

A seemingly easy solution could be to eliminate the valve for Zone 3, and connect it directly to the manifold. The reason I’m hesitating with it is that if I go this way, the garden hose P3 feeding manifold MF2 would be pressurized even when not needed, i.e. when operating Zone 1 & 2. I don’t know if it’s a bad idea or not; I generally prefer not to keep garden hoses under pressure, but maybe given the fact that either zones 1 or 2 would be open, maybe it’s not so bad.

Can you please share your recommendations for such a setup?

Thank you!

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Hi Ron.
Your diagram is pretty straight forward and informative.

The idea of a master valves is good in this instance so that your hoses are not always pressured up as you stated.

It would still be necessary to run your splitter after the master valve instead of being out of zone 3. Currently, there is not way to fire to stations at a time with the Rachio controller.

The hose will only be pressurized as long as the Master valve is open.

In general, is it not recommended to use an individual station as it’s own master valve to another manifold of slave valves since most controllers are designed to run the stations in sequential order according to program start times for that day.

I hope this helps you.


Hi @spscoutenPhD,

Thank you very much for your answer! It gave me the push to eliminate the valve for Zone 3, which does make sense.

I do wonder, though, what is the general recommendation for a layout like I have (which is a very typical one): one main connection point from the home water supply, and feeding zones, some of them close and some of them remote. Seems like the traditional way is still to use a single valve manifold that is close to the water supply, and run pipes to all zones in a hub-and-spoke pattern.
I can’t quite understand why not to use remote valve manifolds, that can spare me from running multiple pipes to an area that is remote from the main water source. To me (maybe because I understand electricity more than water…) is sounds trivial that one should run a single line to the remote area, then have a second valve manifold there (like P3 and MF2 in my diagram). The rationale is that it’s much easier to run and maintain low-voltage electric wires than water pipes.
What am I missing? If it’s so trivial than it would have become the preferred approach. So I guess my logic has a leak somewhere…


And let me explain my logic further about sub-zones. While I understand that traditional dumb controllers would find it hard to support a hierarchy of valves, it’s exactly where I would expect software-run controllers to shine. I’m a software guy so I know it’s possible (well, in software almost anything is) so it’s a matter of motivation more than plausibility.
When we’re discussing a master-slave hierarchy for valves, what we call a Master Valve is actually waiting for a controlling command from any Zone Valve: if any of them is opening, then also open the Master Valve. That’s a 2-level valve hierarchy. In a 3-level hierarchy, like the one I was hoping to get in the original post, it should work like this: Valves (=Zones) 4 and 5 should be configured to be Sub-Zones of Zone 3. Then, when Rachio schedules either Zone 4 or 5 for watering, it knows it needs to also open their local master (Zone 3) and then Zone 3’s own master, which is the Master Valve.
It’s really like a Master Panel and Sub-Panels in electricity planning.
Can it work? Of course. Is there motivation to do it? I don’t know. To me, if such a configuration can help not just watering be more efficient, but also the pipe infrastructure and planning be simpler, safer and less expensive, then it’s a motivation as it’s a great selling point - possibly especially for professionals who can charge the same for less work…
But please correct me if I’m wrong here.

@RonG - Existing Rachio devices are rated to power at most 3 solenoids at one time - due to electrical current going through the circuit board and components. Three solenoids = 1 master valve, 1 previous zone valve and 1 next zone valve (when the reduce water hammer option is enabled). Once can use SPST relays that have a very low draw to fire a second valve when a zone triggers - I’ve drawn up several solutions using relays to solve solutions desired by posters.

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@RonG There is not problem with running a remote manifold. We do it all the time. It is more cost effective to run a longer mainline to join all of the manifolds from 1 central manifold and then just branch out the control wires to the local and remote location under 1 timer location.

@DLane offered a sound work around for the multi valve firing.


@DLane, thanks for the info.
I looked up the posts in which you shared your solution -
Run Multiple Zones At Once and Master Valve only on specific zones, and I get the idea of using relays to get the desired effect.
The point of the water hammer option raising the valve count to 3 is interesting, I haven’t thought of that. Thanks for sharing. I suppose one could consider putting a relay with a delay option (e.g. 5 sec delay) and then you could use the Rachio as the power source. Otherwise you would need your relay-powered zone to use external power to stay within the Rachio’s power limitations, right?

Another option that I’m considering is software based. Since the Rachio has API that can both notify you on Zone status changes and allow Zone control, I could possibly have a service (or IFTTT) that would listen to specific “Zone Start” notifications (in my case Zone 4 or 5), wait 5 sec (same reason as above, to stay within the 3-valve max limit), then open Zone 3 via API. Upon “Zone End” notifications for Zone 4/5, the operation is reversed and Zone 3 is closed via API.
I still like the relay approach a bit more, as it’s more solid than software, but I may still start with the API just for the fun of it.

Hi @spscoutenPhD,

But now I really don’t understand: if it’s common practice to split the zones into multiple valve manifolds, then why won’t a product marketed as a “smart controller” support this scenario which is rather trivial via software changes. I see that the threads discussing this are 4 years old. Rather strange and even alarming.
Or, if the company would not want to support this in software, for whatever reason, they should IMO at least come up with an official recommendation (via relay extensions, API tricks, whatever), rather than leave it to the users to struggle with.
And it’s not only Rachio; seems like modern smart controllers simply ignore this need. Maybe it’s not so common after all?

I will draw you a diagram when I get back to my computer so that you may see how a normal typical system would be set up by the majority of installation technicians or contractors.

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Here is a simple sample of wiring and mainline diagram. Pay close attention to the controller.


The purple boxes are the remote manifolds