Got a problem with a sprinkler system where the switch from zone #1 to zone #2 causes extremely heavy pipe rattling inside the house. This is happening in 9 out 10 runs.
I had noticed a leak between the valve for zone #1 and the house and replaced the valve and some PVC pipe pieces and stopped the leak on that side. There is a small leak behind the valve with minimal water dripping out when that zone is active. It does not (naturally) leak when the valve is closed. After I had replaced the valve and the piping it ran Ok with no rattling for 4 or 5 runs, but then the rattling returned. There is no leak before valve.
Not sure, but can the minor leak behind the valve be causing major pipe rattling? Sometimes the rattling is so bad, the water flow has to be completely stopped and then turned on again (all by hand) to have things calm down.
Zone 1 is the second from the left. The image was taken before the valve was replaced.