After a beautiful summer and in fall the leaves will start changing colors so does your grass. Its time to in a dormant phase until next spring.
At this time, your system needs to be shut down properly and by professionals because all the water in the pipes will need to be drained out using specialized machines.
If you didn’t close your system properly or didn’t shut it down at all, the harsh low temperatures of winter will cause the water to freeze and crack the pipes underground. Then later on and in the summer, when you run your system you will have leaks everywhere and it will cost a lot to fix it.