i am trying to install a sidearm with as little as possible new plumbing ;i have 2 hydrovalves [ball valves] on the end of out and return lines from boiler,within 5 feet of hot water heater , could i plumb the sidearm directly to the hydrovalves and then open them up,would i need to put some kind of check valve in the return line or a circulator on the other line or would the water circulate through the sidearm with just pipes any help or advice ? thanks