It is around 5-6 minutes. When the water is boiling, add the dumplings and stir it a little bit. Cover the lid and let the potstickers boil and float on the top of the water. Then, add 1/2 cup of cold water, cover the lid and let it boil until it floats again. After that, repeat this for 2-3 times. When the dumplings are floating on the top of water, it is a good indicator that dumplings are cooked.