I have heard about water hammer but that seems to be when the water is turned off. My problem happens when the water is turned on. When water is turned on in the bathroom on the other side of the house, pipes start banging loudly but stop after a short while even if the water continues to run.

Is there air in the water lines? What bangs? Hot? Cold? Both? One fixture more then others? Can you give us more details? Regards, Tom