To monitor concentrate flow, a flow sensor with an ungrounded (single-edged) input can be used. The connection for this sensor is marked "CO" and this is active when open. A delay of 1-999 seconds can programmed in step 7.1. Furthermore, it is possible to program the unit to attempt to restart from 0 to 9 times. After this series, the unit can only be restarted by pressing the "ON" key.