Dinamica: "Air in the water cycle".

During the descaling program came the message "Place empty bowl with 1.8l". This is normal when descaling, but always after confirming the process, the pump was briefly actuated and then the message came again. At that point, the water was also really hot.

Then I turned off the machine and replaced the flowmeter, as I had read that as the cause of the error on the net.

Reassembled again, now when starting the machine came the message "Air in the water circuit please rinse hot water". I did, again only short intervals, but now the water was cold.

So I disassembled the machine again and thought maybe I had plugged it in the wrong way. So this time the other way around

The peculiarity now: The water was already boiling hot when rinsing, but there was no end to it. That is, the rinsing process was carried out until no drop of water was left in the water compartment.

What's going on there? Is the plug perhaps broken? Hot water is produced and water/coffee is also produced when the plug is inserted incorrectly.