Zone not starting

My problem is a zone that will not turn on via controller, but will turn on manually.

For some background, I have an older home that came with numerous irrigation issues (controller was dead, valve diaphragms damaged, broken heads). Replaced controller, two backyard valves, and two front heads. Everything works fine now except this one zone.

Here are the details:

• Installed brand new Rain Bird Anti-Siphon Irrigation Valve with Flow Control. Installed same valve right next to it for adjacent backyard zone.
• Opening bleed will start zone fine.
• Opening solenoid manually will start zone fine, but it takes quite a few turns and the base of the solenoid is leaking at that point.
• Flow Control setting makes no difference.
• The backyard valves are close enough to let me swap the solenoids (leaving wired as-is). Swapping the solenoids shows the solenoid is not the problem (the other zone continues to work and the problem zone continues to not run).
• Removing the bonnet did not reveal anything amiss.

Any ideas on what the problem might be?

 

The zone itself at the controller is most likely bad. You did not say what model controller and total number of zones.

1. To further test, check the voltage at the controller for this bad zone when it is activated.
2. If no voltage, remove the wire and check the voltage again.
3. A no load (no wire connected) it could be high as 29.9 vAC for a 24 volt transformer.
4. With the wire connected to a good solenoid it may be anywhere from 18-24 v AC
5. With an ohm meter and with the wire removed for this bad zone, measure the resistance to the solenoid. Should be 20-60 ohms. If no reading, there is an open wire.
6. Move the bad zone wire to a spare zone (port) at the controller and activate that previous unused port. If it works reprogram the controller. You can skip a zone.