Roper Dishwasher Drain Pump Humming, Not Draining:... | appliancefaults.com

Technical Background:

The dishwasher's Main Control Unit (MCU) signals the drain pump to activate at specific points in the wash cycle. This signal sends 120V AC to the drain pump motor. The motor then spins an impeller, forcing water through the drain hose and into the household drain. If the impeller is blocked or the motor is failing, the pump may only hum.

Symptoms:

The Roper dishwasher starts its cycle, washes the dishes, but fails to drain properly. A humming sound can be heard coming from the drain pump area, but no water is being expelled.

Possible Causes:

Clogged drain hose
Debris in the drain pump housing
Faulty drain pump motor
Blocked air gap (if equipped)
Defective drain check valve (if equipped)
Wiring issue to the drain pump

Solution:

1

Unplug the dishwasher from the outlet or turn off the breaker in the breaker panel. Always disconnect power before working on appliances.
2

Inspect the drain hose for kinks or clogs. Disconnect the hose from the drain connection under the sink or garbage disposal and check for blockages. A garden hose can sometimes flush out clogs.
3

Access the drain pump. This usually involves removing the lower access panel and potentially the inner bottom panel of the dishwasher. A 1/4-inch nut driver is commonly used.
4

Check the drain pump for debris. Remove any visible obstructions like food particles or glass shards. Use needle-nose pliers to carefully remove any obstructions from the impeller area.
5

Use a multimeter to test the drain pump motor for continuity. A reading of around 20-120 ohms is typical for a functional motor. If there's no continuity, the motor is likely faulty.
6

If the motor has continuity, check the voltage at the drain pump connector during the drain cycle. You should see approximately 120V AC. Use a multimeter to verify the voltage.
7

If the pump is getting voltage and has continuity but still hums, replace the drain pump assembly. Reassemble the dishwasher and test a full cycle.

Safety Warning:

Always disconnect power before working on the dishwasher. Lock Out/Tag Out (LOTO) procedures should be followed. 120V AC can cause serious injury or death. Wear appropriate safety glasses and gloves.

Prevention:

Regularly clean the dishwasher filter to prevent food particles from entering the drain pump. Run the dishwasher with a dishwasher cleaner monthly to help prevent grease and buildup. Avoid placing large food scraps into the dishwasher.

Expert Tip:

Many Roper dishwashers have a diagnostic mode. Press and hold the 'High Temp Wash' and 'Heated Dry' buttons simultaneously for 3 seconds to enter diagnostic mode. This can sometimes initiate a drain cycle for testing purposes. Refer to the service manual for error codes if any are displayed.

Frequently Asked Questions

•How do I access the drain pump on my Roper dishwasher?

Typically, you'll need to remove the lower front access panel. Then, there may be an inner bottom panel that also needs to be removed. The drain pump is usually located on the bottom left or right side of the dishwasher.

•What type of drain pump should I order for my Roper dishwasher?

Locate the model number of your dishwasher. Use this number to search for compatible drain pumps online or at appliance parts stores. Ensure the new pump is a direct replacement for the original.

•How do I know if my dishwasher's control board is faulty and not sending power to the drain pump?

First, confirm that the wiring to the pump is intact and not damaged. If the wiring is good and the pump isn't receiving 120V AC during the drain cycle, then the control board may be faulty. Replacing the control board is generally a more complex repair and may require a qualified technician.

Roper Dishwasher Drain Pump Humming, Not Draining: Troubleshooting

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I access the drain pump on my Roper dishwasher?

•What type of drain pump should I order for my Roper dishwasher?

•How do I know if my dishwasher's control board is faulty and not sending power to the drain pump?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: