Sprinkle System, Strange set up (so I think)

[Charliebizz]

Hey guys, how are you doing. So I was inspecting my sprinkler system in my new house and I noticed I have 12 zones but only 8 solenoids on the manifold. Then I have 2 sets of wires from the control box. The one wire controls all 8 solenoids and the other one goes under my walk way and controls my front zones. I noticed one of the 8 solenoids on the manifold is being used by the pump slot and if I disable it, the front zones won't work. So it's kind of acting like a master valve for my front zones. I have yet to find the solenoids for the front zones but that's a problem for another day. Any idea why it would be setup like that? Any help would be great, thanks.

 

[WorthFlorida]

More zones than the controller is designed for? Most controllers cannot handle more than 2 solenoids at a time otherwise they can burn out the modules. What is the model number of the controller. Any reason why there is 10 zones or more? Usually you have a very large area to irrigate or not enough pressure to supply large zones so make more zones with less sprinklers.
Some controllers use all modules so if one goes bad you can replace the module or they are built in as with very old units. someone in th epast might have manually turned each zone on to overcome a new controller that can be expensive for some.