Delonghi Ecam25.452S - message circuit empty prime the circuit

Hello, for some time the express has not given milk and a message has appeared to perform descaling, during the descaling the tube supplying steam and water to the frother's clutch was damaged. After replacing the tube, it was possible to complete descaling, but the machine still did not serve milk. I replaced the entire frother clutch with a new one and the machine came to life.
Unfortunately, after making a dozen or so cups of coffee, the problem reappeared, the message "circuit empty, fill the circuit" is still displayed. Please advise.
I greet arthur

Hello,
Can you fix the problem?
I have an identical in my delonghi primadonna S.
greetings

Well, to be honest, I gave up on myself, there is a coffee machine somewhere in the closet, I don't even want to look at it anymore, so much money and it's a pity to talk about such hay

You should suspect the flow meter, no pulses, damaged Hall sensor, dirty impeller.

Welcome back,
I managed to fix the problem, I called the delonghi service, I made an appointment and the problem was solved on the same day.
Some handles and a pump were replaced. The repair cost is 280 PLN.
greetings

I'm closing the topic, replacing two solenoids with new ones and the topic
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