Solenoids not turning off

Hi all. I’m new to Rachio, and just finished installing my irrigation system. I’ve got four zones, all hooked up to a PresFlo pressureswitch, which turns my Pedrollo Plurijet on when pressure after the PresFlo drops (due to opening of the solenoids).

My 4 valves consist of 2 RainBird XCZ-100 and 2 RainBird 100-HV solenoids (all AC). When I switch on a zone everything works snappy and flawless, either through wifi or manually at the controller. When I switch the zone off, it just keeps going. The app confims it stopped the zone, and when manually stopping the zone the corresponding light stops blinking. However, the water keeps flowing.

My first thought was that the diapraghm probably wouldn’t drop, so I manually stopped the pump. After restart, it kept going. The solenoids where turning pretty warm. Only after pulling the plug from the Rachio (2nd gen) the valves would close.

Any thoughts on why this happens?

(I’m in the Netherlands, so I’ m not on the original adapter but a 220v-version (24v, 1 amp, DC) - I do have access to another generic 24v-adapter, so I will test wether this would make a difference)

Alas DC adapters are not compatible with Rachio, you will need to find a 24V AC adapter. Is your other adapter AC or DC?


I just came vack to my topic to tell myself what you just told - never knew those adapters come in AC as well! Usually in- and outside are used for specific polarity.

Found the answer in an old topic from 2015, some 220v-guy with the same problem. Glad to have found the issue! The other adapter is DC as well, so I’ll have to buy a new one…

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What is a Presflo pressure switch and the other device you mention? If you are using DC latching solenoid, Rain Bird is not compatible. I am surprised it is sold in your country. Are irrigation systems popular in The Netherlands?

@Icerunner hi David, any luck finding the transformer? If you don’t have use for the original 110V rachio power supply, I was wondering if you would be willing to open it up for an experiment? Please make sure it is not plugged in while opening it up.

Some transformers come with two primary windings. If the transformer used within the Rachio’s power supply is one of these, we could modify it for 220V operation and you wouldn’t need to hunt for another one.

Of course @franz could chime in and let us know the part number for the transformer within the Gen 2 power supply or at least provide pictures if there is an open power supply somewhere at the factory. Maybe in the future Rachio supply can come with a voltage selector switch, allowing 220V operation with a flip of a DPDT switch.



Pedrollo Plurijet = a waterpump, our backyard lies next to a creek.
Presflo = device directly after the pump, sensing pressure and flow, with a backflow-stop. When the pressure after the PresFlo drops below it’s setpoint, it will switch the waterpump on. The pressure after the PresFlo drops when one of the zone-valves is opened. When the zone-valve closes, the flow drops back to zero, and the PresFlo cuts off the power to the pump again.
This setup protects against dryrunning (no flow - engine will stop).

All my solenoids are AC.

@Gene I will open it up and take some pictures - I did find one that MIGHT work, a Hunter 24VAC with 2x500ma - but just one output connector, so I’m hoping they use some weird way to communicate their ampères… (AC - 500ma one way, 500ma the other way…?)

Ohw, and for popularity: yeah, very… All companies I talked to where swamped with work.
I bought the Rachio from Amazon, directly from the States… Cheaper then the currently available wifi-systems here!

Just found the same transformator used by Rachio in different variants (3 types of plugs and corresponding voltage 120/230v as needed!

Modelnumber matches! Nice :smile:

I would be very careful of this “universal” transformer (especially one without any reviews and voltage ratings blurred out in the picture). Without any sort of switch, you will likely get 2x voltage output, 48VAC instead of 24VAC, and fry everything.

One thing you could look for is 220v to 110v step down converter, like this one (link).


Edit: Seeing their other listings, it seems that they are selling several different adapters under the same listing, customizing them based on where you are ordering from. At least this is what I hope they are doing. DO NOT use this adapter if it comes labeled for 110V operation, I advise you to contact the seller and ask for a better picture of 220V rated adapter prior to ordering it.

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I see what you mean… Sketchy. The Upbright logo is edited in as well. The modelnumber ‘MKA-####’ comes from ‘Merry King Adapters’, for what I can see in other reviews they don’t delivere what is pictured, but just their own generic version.

@Icerunner I agree with Gene. I could not find any 220VAC to 24VAC transformers readily available other than that one on Amazon. The generic step down is probably your best bet. It should just be capable of at least 30W, which that one is.

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Hi, Today I replaced my old Rainbird with a Rachio gen 2. I to live in The Netherlands and found out that I ordered the wrong power supply. A 24V DC.

I just ordered this:

Hope it works. Did you ever found one?

How come that the Rachio Controler works with a 24V DC? But that the valves are not working properly?

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I actually did find one. AC isn’t a problem for most electronics, it’s more that it’s a problem for the valve: the valve works by pulling up a small piston with an electromagnet. An electromagnet will change it’s field following the change of current in AC (it’s short for Alternating Current), so it will alternate between pulling and pushing (oversimplified).

When I’m home, I’ll check what type of adapter I finally found, can’t remember where I bought it… I also got it tucked away in the outdour housing of the Rachio (after some mild tearing apart).

This is the one I’m using:


I am using this one to use the original Rachio power supply:

maybe a stupid question, but Rachio 3 requires 1000mA, is a 2x 500mA the same as 1x 1000ma ?

Not a stupid question, was wondering the same myself. Since there is only one output, there can’t be such thing as 2x 500mA output - I guess it has to do with the AC (Alternating Current) - 2 times 500mA both ways, thus equalling to 1000mA effectively. Anyway: it works :slight_smile:

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