Installation of Rachio 3 with Pump Motor & Electric Zone Valves (Previously Intermatic Timer & Mechanical Indexing Valve)

Hello all!

I’m happy to report that I finally finished up the conversion from the old Intermatic timer with an indexing valve to the new Rachio 3 irrigation controller with electric zone valves. Below is an image of the irrigation system I had for many years and an image of what the heart of my irrigation system looks like now. “Thank you” to those of you who answered the questions I had before I began this conversion! If anyone has any questions about this particular type of setup, please feel free to ask.

Thanks, again!





Looks very clean and professional! How long has it taken you to setup and convert everything?

I assume the tank you’ve removed was for some sort of water additive? Rust remover?
With the old system, did 220V -> 110V transformer double as some sort of relay? It is interesting that the pump used to be connected to the power directly, and now an additional pump start relay is needed.

Have you experienced any issues with the back-flow? I’m assuming that the lake level is lower than your sprinkler heads and the water will gradually flow back into the lake while the pump is off. You may wish to consider adding a one way valve in order to prevent dirt from clogging up your new valves after some time. Irrigation valves like yours are designed to selectively prevent flow only in one direction, in case where the pressure on input is lower than output, they will not do anything to prevent the flow in reverse direction.


@ZoneOne Thanks for sharing, that is a true work of art!


Thank you, Gene!

I was able to convert the electrical side of the project on Saturday, but I had to do it between thundershowers. It’s been raining non-stop in South Florida lately, so outdoor time has been extremely limited. On Monday, I only had time to cut out the diverter valve, but I was able to actually finish the plumbing side of the project on Tuesday. All in all, it took a few hours to complete the whole project, but the results were very satisfying in the end!

The tank was there for a fertilizer project that I put together many years ago. The idea was to use a metering system to inject a pre-diluted fertilizer into the pump while it was running water to the lawn. It worked, but then I just went back to manually fertilizing my lawn a few years later, so the tank and metering system sat unused from that point on.

The one good thing that came from having the metering system is that I was able to reuse the step-down transformer from the metering system to power the Rachio controller. I didn’t have to run a separate 110V electrical line from anywhere for that. I simply disconnected the metering unit and rerouted that existing 110V circuit into the Rachio outdoor enclosure.

With the previous system, the pump was controlled by a 220V Intermatic timer. Since the Rachio only outputs a 24VAC trigger signal, a pump start relay must be used to turn the pump on and off. The PSR is simply a 220V switch that is activated when the Rachio controller sends it a 24VAC signal.

No, there is not a problem with the pump losing its prime because there is a brass check valve at the lake where the pick-up filter is. The only thing I’m missing there is a 100 mesh filter. With the old system, the diverter valve continued to function if small particles made their way through the regular filter screen that originally came with the pick-up filter. With electric zone valves, however, it is recommended that a 100 mesh screen be used to filter the particulate so that the valves don’t malfunction. I ordered a 16"x16" 100 mesh stainless steel screen piece online and will install it onto the exterior of the pick-up filter when it arrives. The lake I pull water from is clean and free of algae, so I don’t foresee any issues with clogging.

Please let me know if you have any other questions and I’ll be more than happy to answer them for you!


Thank you, Franz! I am very happy with the end result and am now learning how to set up the array of parameters within the Rachio app. I am absolutely certain that questions are in my immediate future! :grin:

Thanks, again!

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Where did you find the step down transformer you are using? I would think it would be easy to find but having trouble finding a simple one made for outdoor use.

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I purchased the one I have many years ago at Grainger, but I just did a search and found this one for you:

If you can, try waiting for one to get listed on eBay. They’ll likely list on there for much less.

Did you encounter ant problem with the electrical interference by installing the relay so close to the Rachio controller? Rachio recommends relays should be installed at least 15 feet away from Rachio 3.

None, whatsoever. Everything has been working as expected.

Thanks! Will it be possible for you to share a picture of the wiring exposing how they are connected? I have a similar setup that I want to complete but not sure how to do it. Thanks again for your time in advance.