I just moved into a house in which the sprinkler system has been winterized. I want to get it going again, but I'm not sure what to do about these four valves here.
The previous owner told me that I need to go under the house and open a valve to deliver water to the sprinkler system. I did that that and may or may not have turned the two blue knobs (can't remember what state they were in originally), and water started spraying out of the four valves in the picture above.
I can tell from looking at it that I'm probably supposed to get a screwdriver and tighten or close those valves. But I don't want to make an educated guess and damage the system. Should I completely close off all four of them?