Connecting Hydro-Rain HRC-100 Wireless Rain Sensor to Gen2

The builder of our home installed a Hydro-Rain HRC-100 Wireless Rain/Freeze Sensor connected to a Hydro-Rain HRC-100 C Irrigation Controller. The Sensor (Photo 1) is apparently powered by two 24VAC OUT terminals in the IC (Photo 2). I just purchased a 16 zone Gen2, and want to find out whether the existing HRC-100 sensor is compatible, and if so, how do I wire it to the Gen2, and program it. If it is not compatible, what is the best wireless Rain/Freeze sensor that you would recommend that is compatible with the Gen2?

Photo 1

Photo 2

@joephoto, thanks for reaching out and joining the Rachio community.

Wireless rain sensors have to double up a wire on the “SC” terminal in Gen2 – this support article has a good visual to reference.

For the Hydro-Rain HRC-100 Wireless Rain/Freeze Sensor, I’d recommend the following wiring setup:

Red 1 - SC
Red 2 - SP
White - SC
Yellow - S1

Don’t forget to enable your rain sensor after wiring it up. The support article above references the steps to do so :wink:

Hope this helps.

Best, Emil

@emil you rock.


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Thanks for the quick response @emil!

You’re very welcome @joephoto. Let me know if you run into any issues with this wiring.

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