It’s 20 degrees here and snowed about 4 inches. My system is set not to run under 40 degrees. This afternoon one zone randomly started by itself. There’s no log of the run in the app and no way to turn it off. I had to physically shut the water (yes I know I should have turned it off earlier).
Has this happened to anyone ?
I have seen that happen to a neighbor a few years ago. What happened with in their case is that it starting to freeze the water in the pipe which cause the water to expand and opened the valve. They live over a bump in the road from me, which I do not go that way. They were out of town for a couple of days after that and found their yard has some nice ice formations. We had to chip through a small section of the ice to shut off the water. King drains in the low spots and shutting off the water should prevent that. Some people also blow out the pipes before they freeze, especially if they do not have the king drains everywhere needed.
I am not positive if the above applies to you or not, but seems like a good possibility to me.
Thanks. This certainly sounds plausible since the water was not turned off properly.
For the “fun” of it, here are the couple of pictures I took from Fri, 01 Jan 2016. It actually was beautiful.
To add to @Thomas_Lerman, I would check the valve in question (and all of them for that matter) for any cracks in the body due to possible freezing and running of the valve. Otherwise, you may have a lot of zones start running on their own!
Consider yourself lucky. Last year, I blew my lines out, but we had a warm spell in Feb. I decided to burn down my ornamental grasses, and wanted the hose at the end of my irrigation lines, so I turned it on. A couple weeks later we had a cold spell and after a couple days it busted my backflow and a geyser flooded my yard and onto my neighbors driveway. While replacing my BFP, I broke the elbow down in the ground, so had to dig up a bunch too.
You can blow the lines out with a regular air compressor, just open a valve before you apply the pressure, and set regulator on your compressor output to to 70psi.