Hotpoint Dishwasher Drain Pump Humming: Troubleshooting... | appliancefaults.com

Technical Background:

The dishwasher's Main Control Unit (MCU) initiates the drain cycle by sending a 120V AC signal to the drain pump relay on the control board. This relay then closes, providing power to the drain pump motor. The pump motor then rotates the impeller, which forces water out of the dishwasher through the drain hose. A lack of voltage or a physical obstruction can prevent the pump from moving water. Internal winding failure within the motor also prevents operation.

Symptoms:

The homeowner reports that their Hotpoint dishwasher is running through its cycles, but water remains at the bottom of the tub. They hear a humming sound coming from the drain pump area, but no water is being pumped out.

Possible Causes:

Foreign object lodged in the pump impeller housing.
Clogged drain hose or air gap.
Defective drain pump motor or windings.
Faulty drain pump relay on the control board.
Kinked or blocked drain line connection to the garbage disposal or sink drain.

Solution:

1

Disconnect power to the dishwasher at the breaker panel. Lock Out/Tag Out (LOTO) is essential.
2

Access the drain pump. This typically involves removing the lower access panel and the kick plate using a 1/4-inch nut driver.
3

Inspect the drain pump for visible obstructions. Remove any debris (glass, food particles) carefully using needle-nose pliers.
4

Disconnect the drain hose from the pump. Check for clogs by blowing through the hose or using a shop vacuum. Ensure the air gap (if installed) is also clear of debris.
5

Use a multimeter to test the drain pump windings for continuity. A lack of continuity indicates a faulty pump. Expect to see a resistance reading, typically between 15-30 ohms.
6

If the pump windings are good, check the voltage to the drain pump during the drain cycle. You should measure approximately 120V AC at the pump connector. If no voltage is present, the issue might be with the control board or wiring harness.
7

If the pump is faulty or the control board isn't sending voltage, replace the drain pump or consult a qualified technician to diagnose the control board issue. Reassemble the dishwasher in reverse order.

Safety Warning:

Always disconnect power to the dishwasher at the breaker panel before performing any repairs. High voltage is present inside the unit. Use Lock Out/Tag Out procedures.

Prevention:

Regularly clean the dishwasher filter to prevent food particles from entering the drain pump. Avoid placing large or sharp objects in the dishwasher that could damage the pump.

Expert Tip:

Many Hotpoint dishwashers have a service mode that allows you to manually activate the drain pump. Consult the technical sheet located behind the kick plate to enter service mode and test the drain pump independently.

Frequently Asked Questions

•What is the typical lifespan of a Hotpoint dishwasher drain pump?

The average lifespan of a Hotpoint dishwasher drain pump is typically 5-7 years, depending on usage and water quality.

•Where can I find the tech sheet for my specific Hotpoint dishwasher model?

The tech sheet is usually located in a plastic sleeve, attached to the inside of the dishwasher's kickplate or behind the lower access panel. It will provide specific troubleshooting steps and service mode instructions.

•How do I know if the control board is sending the correct voltage to the drain pump?

Use a multimeter set to AC voltage. Place the probes on the drain pump connector terminals during the drain cycle. You should read approximately 120V AC. No voltage or significantly lower voltage indicates a control board issue, or a wiring harness problem.

Hotpoint Dishwasher Drain Pump Humming: Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the typical lifespan of a Hotpoint dishwasher drain pump?

•Where can I find the tech sheet for my specific Hotpoint dishwasher model?

•How do I know if the control board is sending the correct voltage to the drain pump?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: