there may be a little water in the lines...and when people hear that they freak....the concept of blowing out is to relieve water so that the lines arent chock full. If a little water lays on the bottom of the pipe and that freezes, it has plenty of room to expand, causing no damage. If the pipe is full there is no place for the frozen water to go but out the pipe, which causes a crack. If you want to make sure, (if the zone is spray heads) you can turn the screw down on the nozzle to turn off the middle heads, leaving the last two open..thus it will be able to push further......let me know what happens
Thanks
Ray
Rays Above and Beyond Automatic Lawn Sprinklers