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Irrigation/Irritrol RD-900 won't turn on anymore



I have an RD-900 that has worked perfectly since we bought our house in 2007. I noticed the sprinklers stopped coming on this week, and found my RD-900 completely off when I went to check. I can't get any display to show on it, much less any of the functions to work. I've confirmed the fuse is still good and the outlet (power source) is in working order. Nothing out of the ordinary happened this week - it runs 3x a week on 8 zones, it's been highs of upper 70s here in southern california the last couple weeks. I do notice I have a few spider webs, dead leaves and other very small debris/dust inside the panel when I open the door but that's it (it's actually been that way for years). Thanks for any tips to try!

ANSWER: Hey Tyson, first thing to do, is to see if you have a 9 volt battery installed in the controller. If you do, disconnect it from the controller, turn the power off to the controller for about 1 minute, then turn the power back on. Now see if you get a display. If you still do not get a display, look in the back of the controller, and you will notice a yellow and a red wire hooked to the terminal board, and it will be marked 24 volts. Take a ohm/ volt meter and check the voltage across these two wires (red and yellow) and see if you are getting 22 to 26 volts. If you are, then the transformer is good, and your panel is bad. If you are not getting the proper voltage, then the transformer is bad, and you need to replace it. If the panel is bad, you can either have it repaired or replaced. To remove the panel, you need to un-plug the grey ribbon of wires from the back of the terminal board, and then simply pull the panel straight out from the plastic hinges. Good luck and have a great day.

---------- FOLLOW-UP ----------

QUESTION: Thanks, Jim. I did NOT have a 9 volt battery installed so I tested the board with the volt meter. I found the reading to be 26.xx volts (using my multi-meter's ACV setting - I assume that's the correct setting?). For fun, I then installed a brand new 9 volt battery, and the panel display comes on! With the battery I'm able to set schedules, etc. but it is not turning on the sprinklers, even with manual mode. Perhaps the battery is only meant to save settings and not actually run programs (control sprinkler valves?).

I also noticed once after unplugging for a few minutes, that the display came on when I plugged in (w/o the battery). It worked for a couple minutes, then went off again. I can't repeat this though. Now, I just see the display come on for a split second every few times I plug it in (again, w/o battery). Not sure if this extra info helps to confirm if the panel is indeed bad. If so, where do you recommend I go to buy a replacement panel or get this one fixed? Thanks so much for your help!

Hey Tyson, you are correct, all the battery does is back up the memory if the power goes out, but will not run the system. The panel is bad, if you do not get a display with the battery disconnected. Not knowing where you live, I would suggest looking for an irrigation supply store. Most suppliers carry Irri-trol products, and especially the Rain dial controllers. You can also contact Irri-trol at 1-800-634-8873 and, if you want to send it to them, they can repair it for you. Thanks and have a great day.


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Jim Schaefer


Any question regarding sprinking systems,installation,repair, and trouble shooting.


I have been installing and repairing sprinkling systems since I was 15 years old. Have owned my own sprinkler system contracting business for over 26 years. It is basically the only job I've ever done, except for being a paper boy when I was young.

High School diploma and 3 years college credits.

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