One zone won’t shut off until manually turning on another zone

post by taoc on May 19, 2024

I have a Rachio 3 which has been running smoothly for a few years until recently.

After setting a fixed daily schedule for one zone following over-seeding this spring, I noticed that the zone would not shut off after the scheduled time. The only way to stop it is by manually turning on another zone, which then causes the problem zone to shut off. The same issue occurs during a Quick-Run on this particular zone, requiring the same workaround to stop it.

I’ve deleted and reinstalled the app, but the problem persists.

Any help would be greatly appreciated.

post by Thomas_Lerman on May 19, 2024

Have you checked out the valve? It is possible that the valve is malfunctioning (maybe a dirty diaphragm) and when you turn on another zone, that causes a drop in pressure which allows the first zone to shut off. When the first zone is running when it should not be, try disconnecting the zone wire. If it stays running, you know it is probably something with the valve.

post by taoc on May 19, 2024

Thank you for the quick reply, Thomas.

I haven’t checked the valve because I’m not sure where it is located (I suspect it is buried near the outdoor blowout pipe). However, I did try disconnecting the problem zone wire after the zone was supposed to be off, and sure enough, the sprinkler stayed on. It looks like I have a bad valve.

Thanks again for your assistance.

post by Thomas_Lerman on May 19, 2024

No matter what, I think you will need to find the valves. Likely, a good cleaning or rebuilding might fix it.