Crockpot Chicken and Dumplings

4 chicken breasts, no skin, no bone,
2 cans cream of chicken soup, condensed -- (10.75 ounce) (I used 98% fat free)
1 onion -- finely diced
1 package refrigerated biscuits -- (10 ounce) torn into pieces

Place the chicken, soup, and onion in a crockpot, fill with enough water to cover. Cover the crockpot, and cook for 4 to 5 hours on High. Cut each biscuit into 8 pieces. About 30 minutes before serving, place the biscuit dough in the crockpot. Cook until the dough is no longer raw in the center.