Inspect Your Rain/Freeze Sensors Before Winter Arrives

an image of a flower covered in frost

If you’ve ever used an ice tray, then you know that water expands when it freezes,making the cubes hard to remove. While this has the benefit of making the cubes stay in the tray, that same principle of expansion is not a good thing for your irrigation system.

Water expansion can break some of the most expensive components in your irrigation system and cause issues that you may not even discover until the Spring.

Tuesday, December 21 is the first day of Winter, but Texans, on average, get their first frost in mid-November. Since that time has come, not only is it time to get your system checked and winterized, it’s now also a state requirement.

If your property has a commercial irrigation system, the state of Texas requires that you have rain/freeze sensors installed and working properly. If you don’t, you could face significant liability if we experience another ice storm or severe rain conditions. Therefore, we’ve put together this helpful guide that explains how rain/freeze sensors work, so you’ll be ready for the winter months ahead.

How a Rain/Freeze Sensor Works

A rain/freeze sensor is a measuring device that detects freezing temperatures and rain events. When one of these occurs, the system shuts down the irrigation process to conserve water. This protects your plants from damage caused by overwatering and prevents ice from forming on driveways, sidewalks, and other high-traffic areas.

Sensor Location is Important

Rain/freeze sensors should be installed in areas where the sensor won’t pick up artificial temperature fluctuations, such as under a tree or near a ventilation system. It’s best to avoid areas near anything that gives off ambient temperature such as heating or laundry vents, A/C units or boiler rooms. In addition to triggering water cycle changes, sensors also record temperatures, so extreme variations like direct sunlight and shaded areas can cause false readings. For optimal performance, select a location where the rain-sensing head of the sensor will receive direct rainfall and as much sunlight as the grass. The sensor should extend beyond the line of the roof, obstructions and tree limbs.

Rain/Freeze Sensor Limitations

Even though a sensor will stop the irrigation process when freezing weather arrives, it’s essential not to be complacent. Don’t assume that water hasn’t already turned into ice, especially in areas like sidewalks where there is a lot of pedestrian traffic. This has led to many unnecessary accidents and tragedies that could have been averted. Whenever personal safety and property are at risk, use your sensors as reinforcement for existing safety standards.

What to Do if There’s a Freeze Event

In the event of freezing weather, shut off the flow of water at the source by closing the irrigation system’s double check valve. Once the bad weather has passed, you can then reopen the valve. Remember that it’s your responsibility to prevent the system from running during a freeze event. EarthWorks is not responsible for doing this, so be prepared to act quickly when a storm arrives.

We cannot guarantee that your rain/freeze sensors will be functional at all times. That’s why we recommend regular visual inspections to determine if they are working correctly. Clean off any debris such as leaves, cobwebs, or anything else that might affect the sensor’s ability to function. After that, you can test them and check the battery.


When used correctly, rain/freeze sensors will save you time, money and keep your plants safe. Texas winters can often produce extreme weather conditions without warning. You don’t want to wait and risk problems caused by another weather event such as “Snowmageddon” in February of 2021. Remember that the state’s requirements create the possibility of liability on your part if your sensors aren’t installed or working correctly.

How Can We Help?

If you need help with testing, please let us know. If any of your rain/freeze sensors need to be tested, we will determine if any need to be repaired or replaced and provide you with an estimate. If you have any questions about rain/freeze sensors, contact our office, and we will gladly answer them for you.


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