Maytag Dishwasher Drain Pump Humming But Not Moving... | appliancefaults.com

Technical Background:

The Maytag dishwasher's Main Control Unit (MCU) signals the drain pump relay to activate during the drain cycle. This relay, when energized, sends 120V AC to the drain pump motor. If the pump motor windings are partially shorted or mechanically seized, the pump may hum due to attempted rotation but fail to move water. A blocked impeller will also cause a humming sound.

Symptoms:

US homeowner reports a humming sound coming from the Maytag dishwasher, but the water is not draining after the wash cycle completes. The interior of the dishwasher remains full of water.

Possible Causes:

Obstruction in the drain pump or drain hose.
Drain pump motor failure (humming indicates power but no movement).
Defective drain pump relay on the control board.
Clogged air gap (if installed).
Kinked or blocked drain hose under the sink.
Excessive suds preventing effective pumping.

Solution:

1

Disconnect power to the dishwasher at the breaker panel.
2

Access the drain pump. Usually located at the bottom front behind a lower access panel, secured with 1/4-inch screws.
3

Inspect the drain pump for obstructions. Remove any debris like food particles, glass, or plastic. Use needle nose pliers.
4

Disconnect the drain hose and check for kinks or blockages. Clear any obstructions. A garden hose can flush out blockages.
5

Using a multimeter, check for 120V AC at the drain pump connector during the drain cycle. If no voltage, troubleshoot the control board. A faulty relay will require board replacement.
6

If voltage is present but the pump still hums, the drain pump is likely faulty and needs replacement. Order a new pump. Use a 5/16-inch socket to remove mounting screws.
7

Reassemble the dishwasher, restore power, and run a test cycle.

Safety Warning:

Always disconnect power to the dishwasher before performing any repairs. High voltage is present when the dishwasher is powered. Use proper Lock-Out Tag-Out (LOTO) procedures to prevent accidental energization.

Prevention:

Regularly run a dishwasher cleaner cycle with vinegar or a commercial cleaner. Scrape food particles from dishes before loading. Check and clean the filter screen regularly.

Expert Tip:

Some Maytag dishwashers have a service diagnostic mode. Press and hold the START/CANCEL button for 5 seconds, then press the HI TEMP WASH and AIR DRY buttons in sequence to enter the diagnostic mode. This can sometimes force a drain cycle.

Follow-up Questions:

Frequently Asked Questions

•How do I access the dishwasher's service diagnostic mode?

While the exact sequence varies by model, a common method involves pressing and holding the START/CANCEL button for several seconds, followed by a specific sequence of button presses like HI TEMP WASH and AIR DRY. Consult your dishwasher's technical sheet or user manual for the exact sequence.

•What if the drain pump is clear, and I'm still not getting 120V AC at the connector?

If the drain pump is clear and you're not receiving 120V AC during the drain cycle, the issue likely resides with the control board or associated wiring. Check the drain pump relay on the control board for continuity. If the relay is open, the control board needs replacement. Also, inspect the wiring harness between the control board and drain pump for any breaks or loose connections.

•How often should I clean the dishwasher filter to prevent drain pump issues?

It's generally recommended to clean the dishwasher filter at least once a month, or more frequently if you notice food particles accumulating in the dishwasher. A clogged filter restricts water flow and can put extra strain on the drain pump, leading to premature failure.

Maytag Dishwasher Drain Pump Humming But Not Moving Water: Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I access the dishwasher's service diagnostic mode?

•What if the drain pump is clear, and I'm still not getting 120V AC at the connector?

•How often should I clean the dishwasher filter to prevent drain pump issues?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: