I have a Hunter Pro-C controller and Rainbird sprinkler heads on my 6 zone sprinkler system. The system had been running without any issues for the last 6 years but recently Zone 1 started acting up. On the faulty zone the sprinkler heads come for a couple of seconds, spray water and go down. The controller shows that zone 1 is still running and it counts down for the specified amount of time and moves on to the next zone. The other 5 zones work without any issues. Can someone please guide me in...