Sprinkler Valve Repair -Stuck On

Hi, great website.

I am wondering if you can suggest what the problem with my system might be.
Its about 2-3yrs old
last week the last 3 stations were all running at the same time and will not shut off.

It was installed by a professional but I did make a map of where all the valves were located before the grass grew over them

thanks for any ideas
Ken

Ken of course was referring to my sprinkler website. Boy, that could be a lot of
sprinkler troubleshooting issues, and I don't have all the irrigation system info that I need.
Let's start here.
1. Sprinkler valves stuck open. It is possible that you had three irrigation valves fail mechanically all at once, but not likely. You could also buy a scratch off lottery ticket and hit that too. So let's discard that for now.
2.Sprinkler Timer Failure. More possible than 3 sprinkler valves going bad at once, but still kinda rare.. Let's troubleshoot this lawn sprinkler problem. Have you unplugged the sprinkler controller? If so, and all three continue to run, then it is mechanical, i.e., sprinkler valve stuck open. If they all (the lawn sprinkler valves) shut down, then it is electrical, but not necessarily that the irrigation timer has gone bad. If you, one by one, disconnect the sprinkler wires from their terminals, and the disconnected sprinkler zones won't turn off, it means that the sprinkler controller is not the problem. From here it gets worse.
Let's say that zones 1,3 and 5 (out of a six zone system) still run together when the 3 and 5 wires are disconnected while zone one is on. That would appear to be "ghosting", where in the field (versus in the controller) some wires are touching. The first place to look is where the field wires exit the building. There could be a splice box, or it could be where a lawn guy was daydreaming while he shredded your wire casing and now they touch.
Another place to look is in the valve boxes themselves for poor wiring connections bleeding through the soil due to proximity.