What Is a Rain Sensor?

The primary function of a rain sensor is to stop your sprinkler system from irrigating the landscape when there is sufficient rainfall to water the lawn naturally.

Preventing sprinklers from turning on during periods of rainfall can help you not only conserve water but also prevent overwatering, which can cause root rot and fungal diseases in your plants. It can also help you reduce the amount of money you have to spend on water utilities by minimizing waste.

How Do Rain Sensors Work?

First, they need to be installed in open areas where they can enjoy direct exposure to the rain should it come down.

This means they should not be installed under trees, bushes, or any other kind of covering.  They should also not be installed anywhere where the sprinklers can wet them, as this will cause a feedback loop that causes the sprinklers to shut off as soon as they have turned on.

The most common kind of rain sensor contains small absorbent discs or grids that expand when they get wet. When the rain falls on the sensor and wets it, it expands until it triggers an electronic signal that is sent to the irrigation controller, instructing it to suspend watering operations. The sprinklers will then cease to operate until the sensor dries out.  Another type of rain sensor uses infrared technology or weight sensors.  Ask us which type is best for your system.