Thanks fro your response. Yes they are all off the same manifold and I have looked inside and it appears that nothing is in there.
This problem just started about 2 weeks ago. This problem is with one zone only I have 6 zones. When this zone turns on, there is barely any pressure. I turn the solenoid just a bit and the water pressure kicks up, I close it and it goes back to no pressure. I have also tried opening the bleeder screw about 1/4 turn and the pressure kicks up also. The guy at our local hardware store said it was the diaphragm, so I replaced it, and still no pressure. I just switched the solenoid from another stat...
