Hello: I speak in code sometimes 😕 A recirculating line is sometimes used to get hot water quickly at taps. Also, sometimes it is a way for sediment to leave the bottom of the heater and get distributed far and wide throughout the plumbing. If you had one, it would be the first suspect in line for your sediment problem. If not, you likely have bits and pieces of a decomposed dip tube floating up and out of the heater. So, if there is no recirc line, you might want to check the dip tube, which lives under the cold inlet pipe.