How do I install a wired sensor or wired flow meter with Rachio 3?


This article is intended for instructional and compatibility purposes only. If you need troubleshooting help, please reach out to the manufacturers directly.

Quick Overview

Wired Flow Sensors

While we recommend using the Rachio Wireless Flow Meter to complete your Rachio 3 Smart Water System, the Rachio 3 Smart Sprinkler Controller is compatible with many wired flow sensors. For a complete list of supported flow sensors, check out this article. 

Rain Sensors

In most installations, a rain sensor acts as a switch; as moisture-absorbing disks expand, they activate a switch that interrupts the circuit from the controller to the solenoid valves. Once the rain sensor has dried out, the switch deactivates to allow for normal operation.

The Rachio 3 Smart Sprinkler Controller is compatible with any wired or wireless normally closed (NC) rain sensor, which activates after rainfall (when the moisture-absorbing disks expand). For more information, see Rain Sensors FAQ.

Wire it Up

Before installing your sensor, take a few moments to read through these instructions in their entirety. The sensor can ONLY connect to the following terminals on your Rachio 3:

  • Sensor ( S1 , S2 ) terminals - use S1 or S2 for a single sensor, NOT both
  • Sensor common ( 24 VAC - ) terminal. This corresponds to the SC terminal on the Generation 2
  • Sensor power ( 24 VAC + ) terminal - for wireless (powered) rain sensors. This corresponds to the SP terminal on the Generation 2.Rachio 3 Wired Rain Sensor


Do NOT connect the sensor to any of the zones.

Installation methods must comply with all applicable national and local electrical codes. If you are unsure about proper wiring practices, have a qualified contractor perform the installation for you.

How to Connect Sensor Wiring

  1. Power off

    Disconnect power to the controller.

  2. Locate terminals

    Locate the sensor terminals(S1, S2, 24 VAC +/-) on your controller and attach the sensor control wires directly to these terminals (in any order).

  3. Power on

    Reconnect power to the Rachio controller.

  4. Enable sensor

    Enable the sensor in the Rachio App Controller Settings


Avoid routing the wire over any sharp edges where damage to the wire insulation may occur. For best results, hide the wire as much as possible by tucking it under shingles and/or moldings. Seal any holes made by passing the wire through structure walls.

Also, either terminal "S1" or "S2" can additionally be used for a second sensor. Configuration in the app allows you to assign a rain sensor or flow sensor to either terminal.


For more information on wiring your controller, visit this article.

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Enable in App

  1. Find "Accessories"

    From the Home screen, select the "More" tab and then "Accessories."

  2. Select sensor

    Next, select "Sensor (S1 Terminal)ā€ or ā€œSensor (S2 Terminal)ā€, depending on where you installed the wire. Configure your sensor by choosing which type of sensor you installed.

  3. Enable sensor

    Enable the sensor by toggling it on.

  4. Select type

    Select the type of sensor you're adding (in this case, "Rain").

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Check if it Works

To test the Rain Sensor operation, please review: How to test a rain sensor.


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