Coffee machine delonghi ec 850 - hot water indicator flashing

Hello,
The "hot water" light (such droplets) flashes in the delonghi ec 850m coffee machine and the only thing the machine does is pour hot water after inserting the nozzle. Do you know what the reason may be?

Theoretically, after installing the nozzle and releasing water through it, the coffee machine should function properly.

Is the water jet correct? Ie does not go "only"?

Do you have a water filter in the tank? If so, please run the water without it.

Maybe I did not precisely describe what it was about. When you turn on the coffee machine, either the "hot water" light is on when the nozzle is inserted or it flashes when it is not there. Nothing else works, i.e. you can not make any coffee because all other controls are off. During normal operation of the machine, after turning on the machine, it "illuminated all the lamps", then when they were permanently lit, you could make coffee. And now only this one works The water from the nozzle flows normally, and removing the filter does not change anything.

Hello,
I am writing for everyone because the topic is already solved, and maybe it will be useful to someone. Such a case is a symptom of air in the coffee machine. It is enough to run about a glass of water through the hot water nozzle and it is all right