Toro GreenKeeper Controller Trips Breaker on Zone 2 After Sprinkler Changes

8 zones. Zone 2: water shoots few seconds, then breaker trips. Resets after ~1 hour. Started after replacing 4 pop-ups with risers (2x 4ft, 2x 2ft shrub heads). 8 heads total in zone.

Sprinkler Change Not the Cause

Tony: "Replacing the sprinklers should not be the problem. I would suspect a faulty solenoid, the cylindrical device on the valve that the wires are attached to. Make sure also to use water proof wire nuts when replacing the solenoid. Also shut off the water to the system."

Breaker tripping = short circuit in zone 2 wiring or solenoid. Coincidental timing with sprinkler swap. Test solenoid resistance (should be 20-60 ohms); check wire nuts for water intrusion.