SPRINKLER TALK FORUM - You Got Questions, We've Got Answers

valve is stuck open,take it apart and clean it,if that dont work,rebuild it with replacement parts for that particular valve

They are pretty easy to do. Just watch for the spring above the diaphragm and plunger in the solenoid when you take it a part so you don't lose them. Basically take apart the valve and remove the diaphragm..allot of times what will happen is a small piece of sand
or something will get into the valve on the diaphragm and that will prevent it from sealing. So wash off the diaphragm real good and take and pour some water into the bottom of the valve to make sure there is nothing down inside it.
I also will take the diaphragm and look it over pretty good to make sure there are no dents in the diaphragm. If a small pebble or something got into the valve it can create a dent in the diaphragm and then you would need to replace the diaphragm.

Not sure what type of Toro Valves you have but if they are the jar top where you just spin them off..I can't remember
the model number right now. A few years back they must have had some design flaw as
every valve we installed that summer has come back to haunt us.
They will stick on for no reason and kitting them does not always fix the problem.
Sometimes stretching the spring will temporary fix the problem.
But most generally we end up just switching out the whole valve or should I say valves..because
if this is the model you have and you are going to dig up your valve area you might as well replace them all.

Hope that helps
Candance