Question
I have a Toro system. Zone 1 runs for the entire time the the system is on. I have replaced the solenoid and checked the wiring at the controller and nothing seems to fix the problem.

Answer
Hey Dwayne, it is probably either your controller, or the diaphram in the valve. To check if it is in the controller, take a volt/ohm meter and while the controller is running a valve other than #1, check your voltage on the #1 terminal on the back of the controller. To do this, touch the negative lead to the terminal screw marked C(common) and the positive lead to the terminal screw marked #1. If you are getting a voltage reading on this terminal when another valve is running, then the problem is a short in the controller, and you need to replace the controller. If you are not getting a voltage reading on the #1 terminal, then the valve is stuck on, and you either need to replace or re-build the valve. A good website is www.irrigationtutorials.com and it will show you how to either re-build or replace your valve. Good luck and have a great day.