I have a sprinkler Valve that won't close. The timer is working correctly and sends a signal to close but it stays open unless I move the value slightly up or down. I haven't completely burried it which is why I can move it up/down some. The value was new but I thought I got a bad one. So I bought another and replaced it. The second one behaves the same. Does anyone know what's causing this and how to fix it?