Venting system monitoring for a dishwasher appliance

A dishwasher appliance defining a vertical direction, a lateral direction, and a transverse direction, the dishwasher appliance comprising:

• a wash tub positioned within a cabinet and defining a wash chamber;
• a door pivotally mounted to the cabinet to provide selective access to the wash chamber;
• a duct defining a chamber air intake, an ambient air intake, and an air discharge vent;
• a venting system comprising an exhaust fan for urging chamber air from the wash chamber and an auxiliary fan for urging ambient air from outside the cabinet, wherein the chamber air and the ambient air mix within the duct to create a mixed flow of air that is discharged from the dishwasher appliance;
• and
• a controller in operative communication with the exhaust fan and the auxiliary fan, the controller being configured to:
• energize the exhaust fan and the auxiliary fan;
• monitor a power draw by the exhaust fan and the auxiliary fan;
• determine that the venting system has malfunctioned based at least in part on the power draw by the exhaust fan and the auxiliary fan by determining that the power draw is within a first power range and determining that the exhaust fan is operating and the auxiliary fan is not operating;
• and
• implement a responsive action in response to determining that the venting system has malfunctioned based at least in part on the power draw.