Bought my home in the middle of the winter. (Everything covered with snow) Just turned the water on to the sprinkler system for the first time today. Acts like all zones of the sprinkler system are on at the same time. 6 Zones as far as I've found. Water coming out of all sprinkler heads at a very low rate. Hard to believe that all valves are sticking. I have unplugged the sprinkler controller so no valves can possibly have any power on them. Is there a chance that low pressure from a bad leak or bad adjusted pressure regulator could cause this? The system was turned off last year but I can't be certain that the previous owners really winterized the system like I would have.