Rain Sensor Installation (Gen 2)


Rain sensor installation

Spruce accepts many standard “normally closed” rain sensors from a variety of manufacturers.  Passive rain sensors can be installed using the “S1 or S2” input terminals and the “C” terminal located below the S2 terminal.  Powered rain sensors can have power supplied by the 24 VAC and common terminal below the S2 terminal on the Spruce controller.  The diagrams below show a installation schematics using 4 different rain sensors: Rainbird, Hunter, Irritrol and Orbit.

“Normally closed” refers to the operation condition of the rain sensor.  A rain sensor is “normally closed” when the 2 wires conduct if the sensor is dry.  The connection is “opened” when the sensor is wet.  This is the most common type because this allows the sensor to “break” the power connection going to the irrigation valves if rain is detected.

The Spruce controller must be configured to use a rain sensor in the app.  If the rain sensor is not enabled in the app, the system will not delay watering even if a sensor is attached.

The terminals S1,S2,C, and 24V grouped together on the right hand side are for sensor input and power only.  These terminals may not be used for valve common or power and can not be used for powering the unit. 

Enabling the Rain Sensor in the App

If a rain sensor has been installed, the rain sensor will then need to be enabled in the Spruce app.

The rain sensor terminals are setup for Normally Closed rain sensors. This means if a rain sensor is not attached, or incorrectly wired, and the terminal is enabled, it will think there is rain and potentially prevent watering.  Please ONLY utilize rain sensors in schedules after confirming they are wired correctly.

  1. Open the menu using the button in the upper left hand corner, and tap “Add device”.
  2. Scroll down and select “Rain Sensor”.
  3. Select which port your rain sensor is wired into.

The rain sensor status can be viewed and confirmed in the rain sensor settings page.

After a rain sensor has been associated with your controller, each schedule has the option to use the rain sensor as means to skip watering.  See scheduling setup and options on enabling rain delay specifically for each schedule or zone.

Wireless Rain Sensors

Four common wireless rain sensor wiring diagrams are included below.  The diagrams are for reference only and are subject to change by the manufacturer. If there is a conflict, follow the instructions provided by the manufacturer when attaching the sensor. 

Rainbird WR2

Spruce Rainbird Rain Sensor

Irritrol RS1000

Spruce Irritrol Rain Sensor

Hunter CLIK
Spruce Hunter Rain Sensor


Spruce Orbit Rain Sensor

Non-compatible Rain Sensor

Hunter Solar Sync Sensor

This sensor uses Hunter proprietary wiring and is not compatible with Spruce Controllers.

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