Whirlpool Dishwasher Not Draining and Making Loud... | appliancefaults.com

Technical Background:

The Whirlpool dishwasher's Main Control Unit (MCU) sends a 120V AC signal to the drain pump motor to initiate the drain cycle. The motor then activates the pump, forcing water through the drain hose. If the MCU doesn't send the voltage, or the drain pump motor fails, the dishwasher will not drain. Rattling noises usually indicate a physical obstruction or failing motor bearings.

Symptoms:

The US homeowner reports that their Whirlpool dishwasher is not draining after the cycle completes. Additionally, there is a loud rattling or grinding noise during the drain cycle.

Possible Causes:

Clogged drain pump
Foreign object obstructing the chopper blade
Faulty drain pump motor
Clogged drain hose
Air gap blockage
Defective check valve

Solution:

1

Disconnect power to the dishwasher at the breaker panel.
2

Remove the lower access panel using a 1/4-inch nut driver.
3

Locate the drain pump and inspect for visible obstructions.
4

Disconnect the drain hose from the pump and check for clogs.
5

Remove the pump and inspect the chopper blade for debris. Use needle-nose pliers to remove any obstructions.
6

Use a multimeter to test the drain pump motor windings for continuity. A reading of approximately 15-25 ohms is expected.
7

If the motor windings are open, replace the drain pump.

Safety Warning:

Always disconnect power (Lock Out/Tag Out procedure) before working on electrical appliances. Dishwashers operate on 120V AC, which can cause severe electric shock.

Prevention:

Regularly clean the dishwasher filter to prevent food particles from entering the drain pump. Avoid placing large or hard food scraps in the dishwasher.

Expert Tip:

On some Whirlpool models, entering service mode can trigger a forced drain cycle for testing purposes. This is usually done by pressing a specific sequence of buttons. Refer to the tech sheet behind the lower access panel or the service manual for the correct key sequence.

Frequently Asked Questions

•How do I access the chopper blade for inspection?

The chopper blade is usually located at the inlet of the drain pump. After disconnecting power and removing the drain pump, you should be able to access it. Refer to the service manual for detailed disassembly instructions.

•What if the drain pump motor tests good, but the dishwasher still doesn't drain?

If the motor tests good, check the drain hose for kinks or obstructions. Also, inspect the air gap (if installed) and the check valve. A partially blocked air gap or faulty check valve can restrict drainage.

•Where is the drain pump located on a typical Whirlpool dishwasher?

The drain pump is usually located at the bottom of the dishwasher, behind the lower access panel. It's typically connected to the sump and the drain hose.

Whirlpool Dishwasher Not Draining and Making Loud Rattling Noise: Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I access the chopper blade for inspection?

•What if the drain pump motor tests good, but the dishwasher still doesn't drain?

•Where is the drain pump located on a typical Whirlpool dishwasher?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: