The controller will run two valves at once but you will not have sufficient water supply. There is a component called an ADD-A-ZONE. This will let you run two valves from one wire. I have used the Doubler and the ADD-A-ZONE. The ADD-A-ZONE seems to last a lot longer. I have not had good luck with the doubler. The ADD-A-Zone is fairly simple to install and very dependable.