What is a master valve?

I am setting up the Iro and it’s asking whether to use a Master Valve/Pump. What does this mean? I have 12 valves using 4 separate cables but I don’t know whether I have a ‘master’ valve.

@radamio‌ Here is a good description of a master valve.


If you have any wiring questions you can reach out to support@rach.io and we have wiring professionals that would be glad to help you with your install. Thanks and let us know if you have any more questions or feedback.

Thanks, I realize I don’t have a master valve based on that diagram.