Dear good afternoon. I wanted to ask about the next problem I have, the water tank in my house empties overnight (I spend the night when nobody in the house used water) and I realized trying different things that if I leave the only one closed Hot water stopcock that is in the whole house (it is in the laundry room, in the same place where the water tank is installed) just there the tank begins to fill again. But I don't have good hot water pressure. According to the little that occurred to me, I think that there must be a loss somewhere in the house, when closing the stopcock that water leakage from the loss and that is why the water tank is maintained, in addition that loss must be after the stopcock in the path of the pipe, otherwise the tank would run out of the same water if I close the stopcock but the loss was before it. I already broke a wall through which I supposed I could pass a pipe that carries hot water from the laundry room to the rest of the house, but I didn't find anything, no pipe (I played it to start there because that wall had moisture stains outside in The entire plaster, and in turn inside is also rising to the paint by moisture, at first I thought it came from the foundations and now I thought it could be a broken pipe.The other option I thought is to start breaking following the pipe from the beginning , that is to say from the connection with the hot water tank. Anyone with a little more experience that comes up with something or can guide me? I do not know if the problem could be in the hot water tank and that is why I did not want to send me to break half laundry and maybe the problem is another and not a loss. Any help is greatly appreciated. Regards

Note that hot water is not connected to the network inlet.

Thanks for the answers, it was a waste in the hot water pipe, it is already solved.