Rachio Gen 3 12 Zone Controller Not Working

About 1.5 months ago, I replaced my old Pre-2005 Rainbird ESP-8TM controller with a Rachio Gen 3 12 Zone controller from Costco.

Wiring was pretty basic, moved the 8 zone wires and COM wire from the Rainbird to the Rachio. As I have no outlet near this controller, I did not hook up the Rachio Transformer but opted to reuse the Rainbird transformer that was pre-exisiting from the Rainbird (which also requires 24VAC) into the Rachio 24VAC slots. Incoming power from the transformer was measured with a multimeter at 27.6 VAC.

Up until this past Sunday, all was running fine without issue. I attempted to run the system manually via my phone app Sunday and found the controller is offline. There were no issues with the home wifi. I then went to look at the controller itself and found no lights on. I could not run the controller manually either. I disconnected the power wires for 15ish minutes in hopes it would reset. I hook them back up, issue still existed. Held down the Stop button for 10 seconds to try manual reset. Did not work.

Called customer support, they are sending a new transformer but I do not think this is the issue. Shouldn’t the system work with the 24VAC wires already hardwired and installed into the 24VAC slots? Perhaps I am missing something here???

As a side note, to keep newly seeded portions of my lawn watered on these 88+ deg F days, I have hooked the Rainbird controller back up and all zones are back to working without issue. I would really love to go back to the Rachio for the functionality and ability to control from anywhere.

think of the power brick as your dinner table, and the wires you have pushed into the 24vac slots as eaters, the eaters dont them self produce any power

the 24v power brick you plug into the wall energizes the common wire as well as the computer inside the timer. so if that power brick is not sending out full voltage say… 21 volts or is to high at 26volts it may not be enough to get the computer to power on or enough to allow the solenoids to click over to on or may go into a protect mode so it doesn’t fry

could also be the power bricks are fine and the control unit is fried or some type of internal fuse that blew

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@acox13 - NO, the 24 VAC + and - terminals are not rated to have that much current pushed through them. Your Rachio system board is likely fried from hooking up an external transformer to the 24 VAC + and - terminals. @Gene may be able to comment if you can salvage the board by moving some components off an ununsed zone to replace the components messed up on the 24 VAC + or - terminal.

If there is no 120 VAC outlet near by, one can cut the Rachio transformer cord and extend it with wire to make it reach.

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As @DLane has mentioned, the 24V terminals are not designed to handle the full power or otherwise act as an input. At the very least the filter is blown, making the port inoperable.

If the unit works with original power supply, connected to the appropriate power terminal via the barrel connector, than you may be somewhat in luck, if you did not use the 24V terminals besides the power input, you could continue to use the unit without further repair.

It is also likely that when the filter blew, it has shorted to ground, thus creating a short and preventing the unit from operation without repair. Good news is that the filter is not a necessity, unless you are powering a sensor via long wires, if it comes down to it, should be a simple repair.

Long story short, try to power your controller with the original (Rachio) power supply and extension cable. If it works, great, otherwise try to take the controller off the wall, remove the front cover and take pictures of the board.