Abstract: An apparatus dispenses detergent into a warewasher from a reservoir wherein a flow control device controls the flow of the detergent. A sensor measures the electrical conductivity of water within the warewasher and produces a conductivity measurement. A controller operates the flow control device in a first mode in which the quantity of detergent dispensed into the warewasher is determined in response to the electrical conductivity of the water. If the conductivity measurement is determined to be unreliable, the controller operates in a second mode in which a predefined quantity of detergent is dispensed into the warewasher. The reliability of the conductivity measurement is determined based on the amount that the conductivity changes upon detergent being added to the warewasher.

Abstract: Whenever a dishwasher is operated a given number of times or whenever a given number of days transpire, an apparatus performs a process that removes minerals deposits that have built-up inside the dishwasher. The process commences by rinsing the dishwasher interior with water and draining the rinse water. A mixture of water and a chemical that dissolves the minerals is introduced into the dishwasher and a pump circulates the mixture inside the dishwasher for a period of time. Next the mixture is drained out and the dishwasher interior is rinsed again with fresh water.