Do-It Yourself Rain Sensor Check-Up
If your irrigation system is operating during or shortly after a rain event -- your irrigation controller is helping you spend your money on things you don't really need. The simple fix is to install a rain sensor.
Florida Law (Section 373.62 F.S.), requires all automatic irrigation systems to be outfitted with a working rain shut-off device or other technology to inhibit or interrupt operation of the irrigation system during periods of sufficient moisture. To ensure proper operation, sensors should be checked at least once a year. Once every six months is better. Information about types and installation of rain sensing devices is available from the University of Florida.
These instructions are specifically for testing a cork-disc rain sensor. If you have another type, please check with the manufacturer for specific instructions about testing it.
For a cork-disc sensor:
Locate the rain sensor for your irrigation system. Typically, it will be located on the roofline or atop a fence. Check to make sure that the top of the sensor is not obstructed by eaves, treetops or other obstructions that keep rain from reaching the sensor.
Turn on the time clock for the zone nearest the sensor.
Press and hold down the button on top of the sensor. The zone should shut off. (If your rain sensor does not have a button on top, it is not a cork-disc sensor.)
Release the button and the zone should come back on. If it does, the sensor is operating properly.
If the system does not shut off or come back on, check for wiring problems. The device may have to be repaired or replaced. Check the instruction manual or manufacturer's Web site for additional information about your specific brand and model rain sensor.