Hi Okadokie,

When you bought your new rotor heads did you try to match the old head's flow rates? Also, do you know the total flow and pressure your system provides each zone or station? These are the design parameters to design your system in the first place. Your design should be 80% of your system's actual flow rate and pressure. You do this by adding all your head flow rates and make sure the total is below the 80% mark. If you exceed the 80% you have to reduce the number of heads and create another zone. Do the same for head pressure losses. You can find the design head flow rate for your pressure level at the head manufacturer's web site. Good Luck and aloha.