A dialysis system includes: an enclosure; a dialysate pump carried by the enclosure and arranged to pump dialysate to a patient or dialyzer; at least one container connected fluidly to the dialysate pump; a load cell positioned to weigh dialysate located within the container; an accelerometer positioned and arranged to detect a force imparted on at least one of the enclosure and the container; and electronics configured to receive a first signal from the load cell and a second signal from the accelerometer and process the first and second signals so as to determine if an abnormality sensed by the load cell is a system error or a mechanical interference.