Thank you for your advice. I just wonder, if the zone valve is bad, why only one of the sprinklers is on when the zone is off and the others are on only when the zone is on? Isn't the zone valve control the on/off of all the sprinklers in the zone? In what scenario the malfunction valve can cause only one of the sprinklers in the zone fail to shut down? Thanks.
Hi, I have a weird problem with my 9 zone irrigation system which is over 20 years old. I happened only recently whenever I turn on a zone (any zone other than 3), one of the four sprinklers in zone 3 is on as well (not all the sprinklers). I understand there could be controller or cross wire issue if all the sprinklers in zone 3 start together with other zones. However, in my case, only one of the sprinklers starts with other zones. If I turn on zone 3, all 4 sprinklers in the zone start fine. ...