I have an underground sprinkler system. A few days ago a valve got stuck "on" with a loudly buzzing solenoid. I replaced the entire valve with a new one and wired it in, tested, and all was well:

new replacement valve

Today the zone whose valve I replaced randomly turned on even though the program is not set for this time. Turning the system from AUTO (schedule) to OFF successfully closed the valve (and stopped the sprinklers), then setting it back to AUTO kept the valve off... for now.

Typically when a valve is stuck on there's either debris in the line or the solenoid went bad. I ensured both are solved with my replacement valve. So, given that the new valve is still exhibiting quirky behaviour, what could possibly be going on? It must be receiving power to be on at this point so could the controller be going bad? I've had the controller since we moved in 3+ years ago and it has worked perfectly.

  • 3
    I'd suspect the controller based on what you've said. Do you have an extra unused zone on the controller? Or can you exchange two zones? It would be interesting to move the valve to a different controller zone.
    – Tyson
    Commented May 23, 2017 at 17:44
  • @Tyson many unused zones, thing goes to like 15 and we use only 5. I might try moving it to 6 tonight, thanks!
    – Haney
    Commented May 23, 2017 at 17:45
  • Editing in the make/model of the controller might be a good thing as well if we need to go further with this.
    – Tyson
    Commented May 23, 2017 at 18:17
  • 2
    Does your controller have multiple schedules or multiple on times for each schedule? My Hunter controller has 3 different schedules, and each schedule can have up to 4 on times, allowing me to possibly turn on the sprinklers 12 different times each day. Check that none of the other schedules were inadvertently modified by an errant button press.
    – mmathis
    Commented May 23, 2017 at 18:27

1 Answer 1


Today the valve went back on at 12:55pm local time. Also, while it was on, it did show valve 2 active on the display and the 25 minute countdown timer that I normally use for it, so this is 100% the controller.

I could not find any program setting or schedule that had only valve 2 going on at 12:55pm (which also is impossible according to the scheduler of the controller which works only in 15 minute intervals), so I assumed it was some kind of weird or bad programming state, especially since I finished replacing and rewiring the valve around 12:55pm on Sunday (though this may be a coincidence).

Earlier today I did a factory reset and re-programmed my nightly schedule from scratch. We'll see tomorrow whether or not that worked for sure. ;)

EDIT: it worked! Controller was in a weird state, a factory reset fixed it.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.