A dishwasher appliance includes a sump that defines a transition fill level where the cross sectional area of the sump increases. A pressure sensor is operably coupled to the sump for monitoring sump pressure and wash fluid level. A controller calibrates the pressure sensor by monitoring a sump pressure and determining when the wash fluid has reached the transition fill level. A measured transition pressure is taken at this point and compared to a target transition pressure that is known based on the sump geometry. A slope correction factor is calculated based on the measured transition pressure and the target transition pressure to obtain improved pressure readings and wash fluid level measurements.

A dishwasher and method of operating a dishwasher according to a cycle of operation are described herein. The dishwasher includes a tub at least partially defining a treating chamber, a rotatable spray arm comprising a nozzle outlet, and a liquid supply conduit fluidly coupled to the spray arm. A pump can be fluidly coupled to the liquid supply conduit and operated to flow liquid through an aperture in the liquid supply conduit.

Dishwashing appliances and methods, as provided herein, may include features or steps such as measuring an initial pressure in a sump with a pressure sensor, activating a drain pump when the measured initial pressure in the sump is greater than or equal to a first pressure threshold, and starting a timer when the drain pump is activated. Dishwashing appliances and methods may further include features or steps for monitoring pressure within the sump with the pressure sensor after activating the drain pump, recording a value of the timer as a first time when the monitored pressure reaches a second pressure threshold, calculating a time limit based on the recorded first time value, and determining that the filter is clogged when the monitored pressure does not reach a third pressure threshold before the time limit expires.

A method and corresponding appliance for carrying out the method may include detecting insufficient circulation pump pressure or process water flow rate through a circulation pump of the appliance, supplying water to a compartment of the appliance and logging a time period during which the water is supplied to the compartment and increasing the speed of the circulation pump to a target pump speed where the circulation pump pressure or the process water flow rate through the circulation pump has reached a sufficient operational level. The method may include logging at least two circulation pump speeds and a time period during which the water is supplied to the compartment, and estimating the water fill rate based on predetermined difference in compartment process water volume for the logged at least two speeds and the water supply time period.

A method and apparatus for automated particulate extraction from solid parts is disclosed herein, which comprises a test tank (42) and a liquid cleaning medium (46) for washing a test part (48). The principle advantages offered by this invention include the ability to verify that the test tank (42) has met a required tank clean threshold (102) as specified by a percentage reduction of contaminants (78) through the use of a liquid quality sensor (76) which repeatedly measures the contamination level of a liquid cleaning medium (46) exiting the test tank (42). Type I and Type II sampling error are eliminated by verifying that the liquid cleaning medium (46) passing from the test tank (42) has measured contaminants (78) reaching both a maximum value (98) and then falling below a specified tank clean threshold (102) prior to ending the cleaning cycle.

A dishwashing apparatus may include a sump. The sump may include a sump pan configured to couple with a wash chamber of the dishwashing apparatus. The sump may include a sump well coupled to the sump pan and configured to collect the liquid from the sump pan. The sump well may include a well inlet in communication with the sump pan. The sump pan may convey the liquid to the well inlet. A recirculation port extending through a first wall of the sump well. A drain port may extend through a second wall of the sump well. The second wall defines a bottom of the sump well. The dishwashing apparatus may include a controller. The controller may monitor electrical characteristics of a pump. The controller may provide a notification if fluid is not flowing through the pump.

Dishwashing appliances and methods, as provided herein, may include features or steps such as detecting a pressure (P1) at a pressure sensor upstream from a pump while maintaining the pump in an inactive state and activating the pump from the inactive state for an activation period during which the pump remains active to motivate a continuous fluid flow. Dishwashing appliances and methods may further include features or steps for detecting a pressure (P2) at the pressure sensor upstream from the pump during the activation period and initiating a response sequence at the pump based on P1 and P2.

Dishwashing appliances and methods, as provided herein, may include features or steps such as activating the drain pump for an activation period and receiving a pump-status signal during the activation period. Dishwashing appliances and methods may further include features or steps for detecting a pressure (P1) upstream from the drain pump during the activation period, determining a condition at the filter based on the pump-status signal and P1, and directing the drain pump based on the determined condition.

A dishwasher has a treating chamber for receiving dishes for treatment according to an automatic cycle of operation and a dispensing system for storing and dispensing a treating chemistry to the treating chamber during the cycle of operation. The dishwasher may dispense a treating chemistry when a temperature of a liquid in the treating chamber satisfies a predetermined temperature threshold. The temperature of the liquid may be maintained to satisfy the predetermined temperature threshold for a predetermined period of time based on the treating chemistry.

A method of determining a position of a diverter of a fluid circulation system in a dishwasher appliance includes measuring a fluid pressure in a sump of the dishwasher appliance while pumping fluid from the sump into a wash chamber of the dishwasher appliance via a first component when the diverter is in a first position. The method also includes measuring the fluid pressure in the sump of the dishwasher appliance while pumping the fluid from the sump to a filter cleaning manifold when the diverter is in a second position. Based on the measured fluid pressure, the method determines whether the diverter is in the second position.