I have 4 irrigation zones, and one of them is no longer working (the controller counts down, but no water is coming out). I'm relatively new to this place, and don't have the irrigation system plan from the previous owner.

1) I assume each zone has its own control valve, right?

2) Why is it that some of the pipes inside the house are making a funny noise when the irrigation is active? It's not like the water comes from inside the house, from what I can tell. I'm just trying to understand how the system works.

3) And this is the most important: any tips on locating the control valve for the area that's not working?

Thanks!