Universal flo check on return of boiler

Paulied

I have a boiler with 2 zones one circulator has flo check the other zone circulator does not if I put a universal flo check on return side will I be ok

hot_rod

You need check protection on both pumps. Occasionally some systems need a check on the return to prevent reverse or thermosiphoning up the return
Most of the newer circulators allow you to slip a check into the pump discharge.