I've recently run into an issue with my irrigation system where one of the zones is "stuck". When I have the control panel set to "system off" this zone pops up and seems to run endlessly. I have to shut off water to the system to make it stop running.
I notice that if I start with water off to the system, start the desired program, and turn the water on, then all zones runs as expected (however, after the final programmed zone is complete the rogue zone pops back up). If the rogue zone is already running and I start a program, the rogue zone stays up, so 2 zones are running at once, the rogue zone and programmed zone.
I had a repair company come through last week and they indicated they think the control panel is bad. However, it'll now be 2 weeks before they can come back out and the peculiar behavior has me second guessing. Anybody run into something similar before?