Rachio 3 and Hunter Mini-Clik Rain Sensor Trouble

Hi All,

Just finished installing a Rachio 3 to replace an existing “smart” irrigation controller. The reason for doing this was the old one, while it would use a Hunter Mini-Clik rain sensor, would not report or notify when it was tripped.

When Sensor 1 is enabled, the Rachio 3 repeatedly sees the sensor triggered, cleared, triggered, cleared, triggered, cleared, ad nauseam.

I tried adding a 0.1µF disc capacitor across the sensor terminals. Did not solve the problem

Unsurprisingly: The Sensor 2 input does the same thing.

I put a digital multimeter across the rain sensor’s leads. Measures 0.5Ω. I’m seeing 2.1mV AC across the leads, intermittently. (I assume that’s noise from nearby AC wiring. This is all adjacent to the home’s electrical service entry and breaker panel.)

Is there a solution to this problem that does not involve replacing a perfectly good rain sensor?

Replying to myself …

In fact, there is: Wire the sensor correctly!

I had assumed the sensor should be wired to Common and Sensor 1 or Sensor 2. That is true for some sensors, but not simple passive switch sensors like the Hunter Mini-Clik. I needed to wire it to 24V- and the chosen sensor input.

It’s now working correctly.


@jseymour Welcome to the community!

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I can see there’ll be a bit of a learning curve :laughing:

Sticking a bit closely to what I know, I over-rode the R3’s suggestions for each zone and set the times to what I know works for this time of the year. I left Smart Cycle enabled. (Seemed like a good idea.) Hahaha! Program started at 03:01. It will be running until past 15:00 today.

Five minute cycles with thirty minute soak intervals–probably because the zone properties are clay on a mild grade, aren’t going to cut it :wink:

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Are they all in separate schedules? If they are in the same schedule, it should interleave the soak cycles so that something will keep watering while other zones are soaking.

They’re in a single schedule, but the main front yard zone was the only one that was both “clay” and “slight slope,” and it’s the second longest runtime of the eight zones.


And it really, really works :slight_smile:

Got enough rain this evening to trigger the thing and got the notification from our R3.

I have the mini-click working. However, the mini-click drys out too fast. This happened 10 years ago when my previous click was 10 years old. The thing wore out and I was not able to replace the internal battery. I think the same may be happening to me. I get the rain exception, but it resets in one day as opposed to about 3-4 days previously. I may get another.

The Mini-Clik has no battery. It’s a simple mechanism where moisture causes some discs to swell, activating a switch. As the disks dry out they shrink, eventually deactivating the switch.

You can adjust the evaporation rate. It’s in the documentation.