Rachio 3 - Wireless Rain Sensor Issue


Installed my Rachio 3 today and connected my prexisitng Irritrol rain sensor. Everything seems to work fine except that I’ve received a half dozen notifications that the sensor has activated and then deactivated the Rachio. It had rained the night before but I don’t understand why it would turn on and off during the day without any rain. Issue with the rain sensor or Rachio or other explanation?Thank you.

Gen3 schedule didn't run (due to rain sensor)

That usually is due to wiring or maybe a rain sensor that needs cleaning/maintenance.

Here is an article with Irritrol wireless wiring:

This article explain some troubleshooting tips for cleaning/maintenance:



Thank you for the advice. As for the wiring, I followed the instructions from your first link so I assume it is correct. As for cleaning or maintenance, I can’t advise as the sensor is high up on a gutter on my roof. I will see what happens when we get a dry spell.


@franz -After the 8th activation/deactivation notification in the first day, I’ve decided to turn off the sensor in the app until I can get a tall ladder and reach the sensor to take it apart and clean it. Thanks for your help.


I too am having issue with rain sensor. I have a Hunter Mini-Clik sensor which is hardwired to controller. SC and S1 connections. The unit is new and tested with Resistance meter for NC switch setup. I think the new controller has some issues or the software. Need some tech support.


Hey @Bgman-

Can you post photos of your wiring? That would be helpful in diagnosing this issue.

@Loganrun are you having issues with a Rachio 3 or a Gen 2 controller? Wiring photos would be helpful here too.

McKynzee :rachio:




@Loganrun Move that black wire to 24 VAC - and you should be good.

More information here --> https://support.rachio.com/hc/en-us/articles/360003078653-How-do-I-install-a-wired-sensor-with-Rachio-3-


@timber - I’m experiencing the same problem and thought that my rain sensor needs to be cleaned. Could it be a wiring issue as well? I wired as per the FAQ and the picture below.


@Bgman can you post a picture of your setup? Just helps to see the actual wires.


@timber - Here you go.


Hey @Bgman-

Two guesses here:

  1. Try switching those red wires- maybe there is a chance they got mixed up?
  2. Your rain sensor may just need cleaning. How long have you had it?

McKynzee :rachio:


@mckynzee - Thanks for the advice. I was thinking the same thing about the red wires as the diagram notes red (a) and red (b) and I was unsure if there was a difference in which red wire I chose (as they are not marked). I will switch them up and let you know if that does the trick. If not, I guess the only other cause could be a dirty sensor (it was replaced about 5 years ago and has never been cleaned - never knew I had to). Thanks.


@mckynzee - That solution worked! Who knew there was a difference between the red wires? Thanks.


I to have a Rachio 2nd gen with a Hunter mini click wired rain sensor that is only 2 years old. Last year, it worked perfectly, this year I’m getting the same issue as Loganrun snapped a picture of - “rain sensor activated” , “rain sensor deactivated” up to 4 to 5 times. I know its not the wiring, because it worked fine last year and its a fairly new unit only 2 years old. I really think its a software issue since so many of us are getting the problem


After properly wiring my rain sensor I haven’t had any further power cycles.