A peritoneal dialysis system includes a cycler including a pump actuator, a heater and a heating pan operable with the heater, and a disposable set operable with the cycler. The heating pan includes a sidewall forming a slot. The disposable set includes a pumping cassette and a heater/mixing container. The pumping cassette includes a pump chamber configured to be actuated by the pump actuator. Additionally, the heater/mixing container is in fluid communication with the pumping cassette and is sized to be received at the heating pan. The heater/mixing container includes a port configured such that when the port is slid into the slot of the heater pan sidewall, the port is prevented from rotating about an axis transverse to a direction of flow through the port.
