Question
Hello Jim,  I have a Rain Bird system.  The controller is an ESP-TM. I mainly use the system in manual mode. Lately, when I start the system, zone 1 starts and waters for about 15 seconds and then the water stops.  The controller stays on and continues to count down the minutes for that zone. When zone 2 starts, no water sprays.
Any idea why the sprinkler system starts watering and then stops watering while the controller continues? Could this have something to do with the rain sensor?

Answer
Hey Shawn, it could be a problem with the rain sensor, or a problem with a valve, or a bad wire, or even a  problem with the controller. To determine if it is the rain sensor, you can take the rain sensor off of the terminals in back of the controller, and put a jumper wire across the 2 terminals marked sensor. This is basically by- passing the rain sensor. If this does not work, you need to figure out if the controller is putting out power, when the controller is showing it is running. Take a volt/ohm meter, and put the negative lead on the terminal marked C (common) and the positive lead on the valve # that is running, lets say valve #1. If the controller is putting out power, you should get a reading from 22 to 26 volts, if you are not getting a good reading, then the controller is not working right, and should be repaired or replaced. If you are getting a good reading at the controller, then more than likely it is either in the wires running to the valves, or the valve itself. To determine if it is the wires, take the volt/ohm meter and check your voltage at the valve, by touching the leads to the 2 wires coming off of the solenoid on the valve (it doesn't matter which lead is positive or negative when you check your voltage). If you are getting a reading of between 22 to 26 volts, then the wires are good and either the solenoid or the diaphragm in the  valve needs to be replaced. Go to www.irrigationtutorials.com, and this website will show you how to fix a valve. Good luck and have a great day.