This disclosure relates to dialysis systems and methods. In some implementations, a dialysis system includes a dialysis machine with a fluid line and a drain line, a blood line set configured to be connected to the dialysis machine, and a drain apparatus coupled to the dialysis machine. The drain apparatus includes a chamber configured to receive an end of a patient line of the blood line set, an inlet line, an outlet line, and a valve. The inlet line has a first end configured to be coupled to the chamber and a second end configured to be coupled to the fluid line of the dialysis machine. The outlet line has a first end configured to be coupled to the chamber and a second end configured to be coupled to the drain line of the dialysis machine. The valve is configured to control flow of fluid through the outlet line.