LG QuadWash Dishwasher LDP6810SS: Troubleshooting Dull... | appliancefaults.com

Technical Background:

The dishwasher's Main Control Unit (MCU) controls the circulation pump via a relay. A voltage path exists from the breaker panel, through the door switch, high limit thermostat and safety float switch before reaching the MCU. The MCU then activates the relay, providing 120V AC to the circulation pump. The circulation pump forces water through the spray arms for cleaning.

Symptoms:

The US homeowner reports the LG QuadWash dishwasher LDP6810SS is making a dull humming noise during the wash cycle.

Possible Causes:

Failed or failing circulation pump motor
Partially blocked pump impeller
Foreign object lodged in the pump assembly
Defective diverter valve motor
Faulty main control board (MCU) relay supplying power to the pump
Low voltage supply to the dishwasher

Solution:

1

Disconnect power to the dishwasher at the breaker panel.
2

Remove the lower spray arm and inspect for any blockages.
3

Remove the filter assembly at the bottom of the dishwasher tub.
4

Inspect the sump area for any debris or foreign objects obstructing the circulation pump impeller.
5

Using a 1/4-inch nut driver, remove the pump assembly. Disconnect the wiring harness and test the pump motor windings for continuity. A normal reading is typically between 10-20 ohms.
6

Check the voltage supply to the circulation pump during a wash cycle. You should measure approximately 120V AC using a multimeter.
7

If the voltage is present and the pump windings are good, the pump motor is likely failing and needs replacement.

Safety Warning:

Always disconnect power to the dishwasher at the breaker panel before attempting any repairs. Lock Out/Tag Out (LOTO) procedures should be followed. Exercise caution when working with electrical components as 120V AC is present.

Prevention:

Regularly clean the filter assembly. Avoid placing large food particles or hard objects in the dishwasher. Run a dishwasher cleaner cycle monthly.

Expert Tip:

Many LG dishwashers have a service mode. Press and hold the Half Load and Energy Saver buttons simultaneously for 3 seconds to enter service mode. This allows you to run diagnostic tests on various components, including the circulation pump.

Frequently Asked Questions

•How do I access the circulation pump on the LDP6810SS?

After removing the filter assembly and sump cover, you will likely need to remove several screws (typically 1/4-inch) holding the pump assembly in place. Refer to the service manual for detailed instructions specific to the LDP6810SS.

•What is the proper resistance reading for a healthy circulation pump motor?

Typically, a healthy circulation pump motor will have a resistance between 10 and 20 ohms. However, refer to the service manual for the exact specification for the LDP6810SS model.

•How do I know if the main control board relay is faulty?

If the pump motor windings are good, there are no obstructions, and 120V AC is not reaching the pump during the wash cycle, the relay on the main control board may be faulty. Replacement of the control board may be required.

LG QuadWash Dishwasher LDP6810SS: Troubleshooting Dull Humming Noise

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I access the circulation pump on the LDP6810SS?

•What is the proper resistance reading for a healthy circulation pump motor?

•How do I know if the main control board relay is faulty?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: