Change-over valve device, preferably sanitary change-over valve device, comprising - a valve housing , - a fluid inlet into the valve housing , - an inlet chamber within the valve housing , with the fluid inlet leading into the inlet chamber, - an intermediate chamber within the valve housing , in fluid communication with the inlet chamber via a permanently open connection channel , - a first fluid outlet out of the valve housing , in fluid communication with the inlet chamber via a first outlet channel capable of being shut off, - a second fluid outlet out of the valve housing , in fluid communication with the intermediate chamber via a second outlet channel capable of being shut off, - a self-acting fluid pressure-controlled, first shut-off valve unit for opening and closing the first outlet channel , and - a user-operated, second shut-off valve unit for opening and closing the second outlet channel , - wherein the first shut-off valve unit comprises a valve piston which is movable controlled by the difference of a fluid pressure acting upon it from the inlet chamber on the one hand and the intermediate chamber on the other hand between an open position opening the first outlet channel and a closed position blocking the first outlet channel , and - wherein the second shut-off valve unit comprises a valve closing body movable upon user operation between an open position opening the second outlet channel and a closed position blocking the second outlet channel , and - wherein the valve piston assumes its closed position when the valve closing body is in its open position, and the valve piston assumes its open position when the valve closing body is in its closed position, and characterized in that - fluid remains ponded in the intermediate chamber when the second shut-off valve unit closes the second outlet channel , and flows out of the intermediate chamber via the second fluid outlet when the second shut-off valve unit opens the second outlet channel . - a valve housing , - a fluid inlet into the valve housing , - an inlet chamber within the valve housing , with the fluid inlet leading into the inlet chamber, - an intermediate chamber within the valve housing , in fluid communication with the inlet chamber via a permanently open connection channel , - a first fluid outlet out of the valve housing , in fluid communication with the inlet chamber via a first outlet channel capable of being shut off, - a second fluid outlet out of the valve housing , in fluid communication with the intermediate chamber via a second outlet channel capable of being shut off, - a self-acting fluid pressure-controlled, first shut-off valve unit for opening and closing the first outlet channel , and - a user-operated, second shut-off valve unit for opening and closing the second outlet channel , - wherein the first shut-off valve unit comprises a valve piston which is movable controlled by the difference of a fluid pressure acting upon it from the inlet chamber on the one hand and the intermediate chamber on the other hand between an open position opening the first outlet channel and a closed position blocking the first outlet channel , and - wherein the second shut-off valve unit comprises a valve closing body movable upon user operation between an open position opening the second outlet channel and a closed position blocking the second outlet channel , and - wherein the valve piston assumes its closed position when the valve closing body is in its open position, and the valve piston assumes its open position when the valve closing body is in its closed position, and characterized in that - fluid remains ponded in the intermediate chamber when the second shut-off valve unit closes the second outlet channel , and flows out of the intermediate chamber via the second fluid outlet when the second shut-off valve unit opens the second outlet channel . <EOS>