Amana Dishwasher Drain Pump Humming, No Water Movement:... | appliancefaults.com

Technical Background:

The Main Control Unit (MCU) sends a 120V AC signal to the drain pump relay on the control board. When the relay closes, it sends power to the drain pump motor. If the MCU doesn't send the signal, or the relay fails, the pump won't run. Also a blocked impeller will cause a hum with no water flow.

Symptoms:

The Amana dishwasher starts its cycle normally, but water remains in the tub after washing. The drain pump makes a humming noise, but no water is being pumped out.

Possible Causes:

Obstruction in the drain pump impeller
Defective drain pump motor
Clogged drain hose
Blocked air gap (if installed)
Faulty drain pump relay on the control board

Solution:

1

Disconnect power to the dishwasher at the breaker panel.
2

Access the drain pump, typically located at the bottom of the dishwasher. You may need a 1/4-inch nut driver to remove the lower access panel.
3

Inspect the drain pump impeller for obstructions (food particles, glass, etc.). Remove any debris.
4

Disconnect the drain hose from the drain pump and check for clogs. Use pliers to remove hose clamps and a small screwdriver to assist.
5

Use a multimeter to test the drain pump motor for continuity. It should have a low resistance reading (e.g., 20-50 ohms). If open, the pump is defective.
6

If the pump tests good, check the voltage at the drain pump connector during the drain cycle. You should measure approximately 120V AC.
7

If no voltage is present, the issue may be a faulty drain pump relay on the control board; consider licensed technician control board diagnosis and repair or replacement.

Safety Warning:

Always disconnect power to the dishwasher before performing any repairs. Use Lock-Out/Tag-Out (LOTO) procedures. Dishwashers operate on 120V AC; avoid contact with live wires.

Prevention:

Regularly clean the dishwasher filter to prevent food particles from entering the drain pump. Periodically run a dishwasher cleaner to help prevent clogs.

Expert Tip:

Many Amana dishwashers have a service diagnostic mode. Check the tech sheet located behind the kick panel (lower front panel) for the specific sequence to initiate the drain cycle manually for testing purposes. This will allow you to isolate the drain pump functionality more quickly.

Frequently Asked Questions

•How do I access the dishwasher drain pump?

The drain pump is typically located at the bottom front of the dishwasher, behind the kick panel. You'll likely need to remove a few screws using a 1/4-inch nut driver.

•What is a normal resistance reading for a drain pump motor?

A normal resistance reading for a drain pump motor is typically between 20 and 50 ohms. An open circuit (infinite resistance) indicates a faulty motor.

•How do I test for voltage at the drain pump connector?

Use a multimeter set to AC voltage. Carefully place the probes on the terminals of the drain pump connector during the drain cycle. You should read approximately 120V AC. Be extremely careful to avoid electrical shock.

Amana Dishwasher Drain Pump Humming, No Water Movement: Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I access the dishwasher drain pump?

•What is a normal resistance reading for a drain pump motor?

•How do I test for voltage at the drain pump connector?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: