... don’t need release a lot cold water of pipe any more.The water at any one point,we should open ... be out , So do not release all cold water of the pipe. 4,over-time protection function: When the ... economical and practical features: A, to save cold water of hot water pipe; B,Saving a lot of time to release the ... cold water of the pipe; C, when we need to use hot water ,it will work , ...