How to Install a Rain Sensor

A rain sensor is a device that can be attached to your sprinkler system to automatically turn it off when it rains. This minimizes the amount of water that you use to keep your lawn green and ensures that you don’t overwater your grass when it rains. You can easily install a sprinkler rain sensor yourself.

Find the Right Location

The best place for your rain sensor will be where the sensor is exposed to the same sun and rain conditions as the rest of your lawn. It should not be sheltered from the elements by your roof line, trees or other overhead obstructions. Keep the sensor away from water spouts or sprinklers that could spray water on it and activate its shut-off feature.

Set the Rain Sensor

Decide how much water is allowable before the sensor turns off your sprinkler system. Generally you can choose between 1/8 and ¾-inch. Select a setting between 1/8 and ¼-inch if you live in an area that is very dry, gets a lot of direct sun or has clay-based soils. On the other hand, if you live in an area that has high humidity, is normally very shady or has a sand-based soil, set your sensor at between ½ and ¾-inch.

Set the Rain Sensor’s Vent Ring

The position of the sensor's vent ring will impact how quickly it dries out. If you live in an area of high humidity, open the vent ring up a lot to ensure it dries quicker. If you live in an area with low humidity, keep the vent ring lower.

Mount Your Rain Sensor

You will need mounting fasteners that are appropriate for your exterior wall materials, i.e. concrete, brick or wood. The fasteners will secure the mounting bracket to your exterior wall. Position this bracket within 25 feet of your control unit. Finally, use fasteners that come with your sensor to attach the unit to the mounting bracket.

Wiring Your Rain Sensor

If you are installing your sensor yourself, select a model that has a closed wiring system. This means that the wiring is pretty much completed at the factory. All you have to do is plug in the wire assembly to the controller and sensor to make it work.

If you buy a rain sensor that has an open wiring system, you will need to cut and hard wire your system into your home’s electrical system by hand. If you select this option, make sure that you follow your local building codes for electrical systems.