A method for filling an empty system with a liquid product is provided. The system comprising an inlet, a first valve, a tank, a first pipe connecting said inlet to said tank forming a first flow path, wherein said first pipe is provided with said first valve such that said first flow path is closed or open, a second pipe connecting said tank to said inlet forming a second flow path, such that said first flow path and said second flow path provide a circulation flow path. The method comprises closing said first valve such that said first flow path is closed, feeding in said liquid product via said inlet such that said second pipe is filled with said liquid product, opening said first valve such that said first flow path is opened, and feeding in said liquid product via said inlet such that said first pipe is filled with said liquid product.