LG QuadWash Dishwasher: Spray Arm Not Spinning -... | appliancefaults.com

Technical Background:

The LG QuadWash dishwasher uses an MCU (Microcontroller Unit) to control the wash cycle. The MCU energizes the wash pump motor and diverter valve (if equipped). Voltage paths from the MCU through relays and wiring harnesses deliver 120V AC to these components. Sensors provide feedback to the MCU about water levels and temperature. Blockages or failures in the water delivery system will prevent proper spray arm operation.

Symptoms:

The upper and lower spray arms in my LG QuadWash dishwasher are not spinning during the wash cycle. Dishes are not being cleaned properly, and food residue remains after the cycle is complete. The spray arms may be stuck or moving very slowly.

Possible Causes:

Spray arm blockage from food particles.
Low water pressure entering the dishwasher.
Faulty wash pump or motor.
Clogged filter assembly restricting water flow.
Defective diverter valve (if applicable) preventing proper water distribution.
Obstruction in the spray arm nozzles.

Solution:

1

Unplug the dishwasher or turn off the breaker at the breaker panel.
2

Inspect the spray arms for visible obstructions. Remove them and flush with hot water. Use a small brush to clean the nozzles.
3

Clean the filter assembly located at the bottom of the dishwasher tub. Remove any food debris or mineral buildup.
4

Check the water inlet valve screen for debris. Turn off the water supply to the dishwasher before removing the inlet hose. Clean the screen and reassemble.
5

Verify adequate water pressure to the dishwasher (minimum 20 PSI). Check the water supply line for kinks or restrictions.
6

Inspect the wash pump motor for damage or obstructions. A multimeter can be used to check the motor windings for continuity. (Typically 10-20 ohms). If the motor is faulty, replace it.
7

(Advanced) Check the diverter valve (if applicable) for proper operation. Use a multimeter to check the solenoid valve for continuity. Listen for a click when the dishwasher is running the cycle.

Safety Warning:

Disconnect power to the dishwasher before performing any repairs. Use Lock Out Tag Out (LOTO) procedures to prevent accidental re-energization. 120V AC is present in the dishwasher control system. Use caution when working with electrical components.

Prevention:

Regularly clean the dishwasher filter assembly to prevent food buildup. Avoid overloading the dishwasher, as this can restrict water flow. Ensure adequate water pressure to the dishwasher. Periodically run a dishwasher cleaner to remove mineral deposits.

Expert Tip:

To enter the service mode on many LG dishwashers, press and hold the 'Rinse' and 'Power' buttons simultaneously for 5 seconds. This allows you to run diagnostic cycles and test individual components.

Frequently Asked Questions

•How do I remove the spray arms from my LG QuadWash?

Most LG QuadWash spray arms are held in place by a retaining nut or clip. Rotate the nut or clip counter-clockwise to release the spray arm. Some models may have a simple snap-on design.

•What is the proper water pressure for my dishwasher?

The recommended water pressure for most dishwashers is between 20 and 120 PSI. Low water pressure can significantly affect cleaning performance.

•How do I check the wash pump motor for continuity?

Disconnect the power to the dishwasher. Locate the wash pump motor. Disconnect the wires connected to the motor. Use a multimeter set to the ohms setting to measure the resistance across the motor windings. A reading between 10 and 20 ohms is typically expected. An open circuit (infinite resistance) indicates a faulty motor.

LG QuadWash Dishwasher: Spray Arm Not Spinning - Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I remove the spray arms from my LG QuadWash?

•What is the proper water pressure for my dishwasher?

•How do I check the wash pump motor for continuity?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: