I had finished watering my plants one day and had gone inside. The next week I went to go water it and the system didn't start. No water came out at all! All of the valves are on and there isn't anything wrong with the power. It seems to me like there isn't any water even traveling to the sprinkler heads. I am smart in this type of subject (sprinkler systems) but I can't figure out this problem I am having. I was wondering if it could be the rain sensor. It is on active. Should I change it to bypass? Or should I try something else?