[scottz]

Originally Posted by beeje

There is no vacuum breaker/ check valve needed. Our fine government regulations required it to be there. The flush system works just fine without either one in place. The chances of sewage being drawn back into the fresh water system are nil to none since there is no sewage around the spray head when flushing the tank out (if you are doing it correctly). The tank should be drained first before starting the flush.

Agreed, but don't forget to winterize the tank flush.