Zone 1 is always on

When turn on backflow, zone 1 start non-stop watering while other zone follow the setting. What could be wrong with my zone 1? The only way to stop zone 1 water is to shut off my water from backflow system.

I have tried the following and still not able to stop zone 1 watering:

  • quick run zone 1 for 1 minute and it did not stop after 1 minute
  • un-power the Rachio controller and turn it back on
  • disable zone 1
  • change to standby mode

please help advise what can I do to fix my zone 1. Many Thanks.

The most common issue for what you are describing is that zone 1’s valve is in need of cleaning such as a small rock is preventing the diaphragm from shutting all the way off. Try disconnecting zone 1 from the Rachio and it probably will still run. You can check to make sure the bleeder on the valve is off. Another option is the solenoid could be bad.

@Thomas_Lerman is 100% correct. There is an issue with the valve itself, either with a torn or damaged diaphragm, or possibly a bad solenoid plunger.

I had one of my zones do the very same thing a couple weeks ago. I keep spare valves around, and when one is acting up, I replace the whole top section (bonnet, diaphragm, and solenoid) and just leave the valve body in place, and there is almost never an issue with the body.