Commercial Dishwasher Troubleshooting: Why Isn't It Drying Properly?
A dishwasher is one of the most essential appliances in any restaurant or commercial kitchen. Most technicians get calls about a unit not drying dishes and other wares correctly. Not sure what's causing the issue? Don't worry. This guide will help service techs identify potential issues so they can fix it quickly.
What is a Commercial Dishwasher?
Dishwashers are mainly used to wash dishes, cutlery, glasses and other wares. Generally, commercial dishwashers are used in restaurants, hotels, schools and other commercial kitchens where a large number of items need to be washed quickly.
High-temp commercial dishwashers wash dishes with hot water (150-160 degrees Fahrenheit) and then rinse out at a 180° Fahrenheit temperature. However, the temperature varies by company and model. Low-temp commercial dishwashers usually have washing and rinsing temperatures of 120° Fahrenheit and 140° Fahrenheit, respectively.
5 Major Reasons Why A Commercial Dishwasher Stops Drying
You know that the dishwasher is plugged in and there is power, but why won't it dry? One of the five issues below could be the culprit.
1. Faulty Heating Element
One of the most common issues a commercial dishwasher encounters when it does not dry dishes properly is a fault in the heating element. A service technician will need to diagnose this by removing the heating element and using a multimeter to test for continuity.
2. Vent Assembly Blockage or Broken Door Motor (Conveyor)
Many dishwashers use a vent assembly with a motorized door to let out hot steamy air generated during the rinse cycle. If the vent fails to open all the way, the moisture can remain on the dishes. Check the vent assembly to see if it is blocked and open it. If there isn't an obstruction or the issue persists after removing the blockage, the issue could be caused by a broken door motor and will need to be replaced.
3. Faulty Vent Fan Motor
Most commercial dishwashers use a vent fan motor to blow the heated air out of the vent as soon as the rinse cycle is finished. If the fan blades are damaged or the motor itself is defective, the dishes cannot be appropriately dried. Either a lack of continuity or broken blades are going to require a service technician to diagnose and repair.
4. Faulty Thermostat
Dishwashers have high-limit thermostats, which act as safety switches to save them from overheating. If a thermostat malfunctioned, it would turn off the dishwasher and stop the drying process. In this case, a service technician will need to test the thermostat and potentially replace it.
5. Missing or Defective Rinse Aid Dispenser
A broken or lack of rinse aid dispenser won't properly remove moisture from dishes and other wares. Unplug the dishwasher and take off the cap from the inside of the dishwasher door. Check if the rinse aid dispenser is missing, and add it immediately if it is. If it's installed but appears damaged, replace it immediately.