Summerizing

Ok I’m “summerizing” my 2018 320. I’ve loaded a full tank of fresh water and am running that through all the systems, including the alde water heater. There seems to be a lot of air in the system to purge, especially on the hot water side. The connections to the pump are tight and not leaking and no leaks from anywhere under the camper (which I assume I would see if there was a broken pipe). I’ve run about 75% of the tank through, according to the led panel. Is this typical?