A dishwasher that is not drying may have a simple fix, like adding rinse aid or a slightly more complex solution, such as replacing the heating element. To help you determine what the problem is, we have compiled the top 7 reasons your dishwasher is not drying, with instructions for how you can fix each issue.
Read on to diagnose and fix your dishwasher.
How the dishwasher dries dishes
To assist with fixing your dishwasher, it is helpful to know how the dishwasher dries your dishes.
A dishwasher has two main drying methods, either the dishwasher has heated drying or it uses condensation drying.
Typically, heated drying uses the heating element to create very hot air that circulates through the dishwasher before a small fan sends the air out the dishwasher vents. If your dishwasher has a heating element, a fault with the element is often the reason for the dishes not drying.
Furthermore, the dishwasher’s control board sends an electrical current to the high-limit thermostat and onto the heating element, which sends the current back to the control board. If the high-limit thermostat or the wiring that connects the heating components become damaged, the dishwasher will not dry properly.
Condensation drying, which Bosch dishwashers are known for, works by utilizing several dishwasher elements that create condensation within the dishwasher to dry the dishes. Condensation drying dishwashers have a stainless steel tub that quickly cools before the dishes in the dishwasher do after the dishwasher has finished a cycle.
When the hot air on the dishes comes into contact with the much cooler stainless steel tub, the heat and moisture turn into tiny droplets of water that fall off the dishes. The result is that the dishes dry without the need for a heating element.
Here are the top 7 reasons your dishwasher is not drying
1. Not using rinse aid
Rinse aid helps the dishes to shed water and dry quickly. Most major dishwashing manufacturers recommend using rinse aid, with some describing it as mandatory if you want your dishwasher to work properly.
Some dishwashers have a rinse aid dispenser that will dispense rinse aid at the correct time during the cycle. If the rinse aid dispenser is damaged, typically appearing discolored or being warped, you should replace the rinse aid dispenser.
2. A defective heating element
If your dishwasher has a heating element, if it is defective, the dishwasher will not be able to dry the dishes. The heating element is located at the bottom of the dishwasher, either covered or uncovered. If it has a cover, the cover will need to be removed to access it.
The heating element can be tested with a multimeter for continuity (a continuous electrical path). A multimeter reading that shows your heating element is not defective can vary depending on your dishwasher; consult your manual for the correct reading for your dishwasher. However, a measurement of infinite resistance likely means the heating element is defective and needs to be replaced.
3. A defective high-limit thermostat
Dishwashers with a heating element also have a high-limit thermostat that regulates the temperature of the water. If the high-limit thermostat is defective, it may stop the dishwasher from reaching the high temperature it needs to wash and dry the dishes.
Like the heating element, the high-limit thermostat can be checked with a multimeter to determine if it has failed. If the high-limit thermostat has a reading of infinity resistance, it has likely failed and will need to be replaced.
The proper resistance can vary from dishwasher to dishwasher, so check your manual for the correct resistance for your dishwasher’s high-limit thermostat. The high-limit thermostat can be found under the dishwasher tub, accessible by removing the dishwasher’s kick plate.
4. The wiring
If any of the wires that connect the control board with the heating element or high-limit thermostat are damaged or disconnected, it could be responsible for the dishwasher not drying the dishes. Replacing damaged wires or reconnecting wire connectors that have come loose may solve your dishwasher’s drying problem.
5. Dishwasher vents and fans
Many dishwashers have vents with motorized doors to release the hot air from the dishwasher. If the vent doors do not open all the way, the dishes will fail to dry properly. If the vent assembly is damaged, it will need to be replaced. The vents are usually found on the inside of the dishwasher door.
Some dishwashers also have a fan to blow the hot air out of the vents. The fan motor can fail, which will cause the dishwasher not to properly dry the dishes. The fan blade can also become damaged and restrict the fan from doing its job.
The fan and motor are usually located inside the dishwasher door. The motor can be tested for continuity with a multimeter If the motor does not have continuity, it will need to be replaced. Any fan blade that is damaged will also need to be replaced.
6. Dishwasher settings
Dishwashers usually come with different settings, some that work better when it comes to drying your dishes. For example, an energy-saving setting will result in moisture still being on the dishes when it finishes a cycle.
If a heated dry setting is available, selecting it should improve the dishwasher’s drying ability. Other settings, such as “high temp,” may enhance the dishwasher’s drying ability. Consulting your owner’s manual to make sure you are using the setting that is best for you and best for drying may solve the dishwasher’s drying issue.
7. Water temperature
If the dishwasher is not using a heated dry setting, the water temperature must be at least 120 degrees Fahrenheit. As the dishwasher receives hot water from the same source as your kitchen hot water faucet, the temperature can be measured by running the hot water in the kitchen for 1minute, then checking the water temperature.
If the temperature is less than 120 degrees Fahrenheit, the temperature on your home’s water heater will need to be adjusted. When adjusting the water heater temperature, you should not go above 120 degrees Fahrenheit to avoid scalding when using the hot water for other purposes.