Hi Edu. Before the pipe breaks outside, it is normally filled with the pressure of the net. Will it be air in the pipe?
It would be necessary to control the pressure to ensure that it is sufficient to reach the tank, verify some intermediate key and the closure of the tank float that is not stuck. After that there is not much left to do, although generally when the pipes run out of water they usually give off waste (especially metal pipes). Regards
Thank you! The plumber came, left everything open. I check the stopcocks. After. After a while, air started to come out and he is carrying the toilet bag now. According to him it's air in the pipe