There are so many different ways to troubleshoot a sprinkler system not properly working. For example, a particular zone was not shutting off and we ended up having a record water bill. I did some digging, and I later determined that a rubber diaphragm inside a valve bonnet needed to be replaced. Sometimes dirt or rocks can obstruct the valve, but in this case, the rubber seemed defective. I ordered a new valve, took out the bonnet from that valve and replaced it on the old valve without removin