[Solved] Citroen C4 1.6 2007 16v - Losing coolant, you can see more in the video. What is

A week ago I had to add 2 liters of coolant. Until today, nothing has disappeared and I have not noticed the "stain" anywhere. Today there was a couple from under the hood, after opening it I saw what is shown in the attached video.
I added another two liters and tomorrow I return the car to the mechanic. I'm pretty green on this topic, can anyone on the basis of this video tell what happened and how much the repair will take me?
The engine works evenly, the power remains unchanged, it does not smoke, it does not go out, it has kept the perfect temperature until today. Now, when the steam appeared, of course it showed me a sudden increase in temperature to the maximum, there was also a red "stop" indicator. Oil neither increases nor decreases.

Check fluid hoses, one may be cracked or have a poorly tightened clamp. A boiling symptom and a leakage of liquid may indicate a defective head gasket or thermostat. Does your radiator fan work, check the fuse and it turns slightly.

The connection at the head has broken. Thermostat housing, new from 70 PLN. The entire repair should be closed in three.

The fan works like a doll, in the video you can see where the fluid is leaking. I hope to put in the 300 zlotys, thank you for the information

I had the same problem. You can easily fit in 300 PLN

It was exactly what indicated, thank you