LG Dishwasher LDS4821ST Repair Manual

The LG Dishwasher LDS4821ST is a 24-inch built-in dishwasher with stainless steel tub, multiple wash cycles, adjustable racks, delay start, child lock, and energy-efficient operation. This repair manual covers safety precautions, troubleshooting, component replacement, and maintenance procedures for qualified technicians. Below are key sections for safety, features, disassembly, repair procedures, and troubleshooting.

1. Features at a Glance 2. Safety Precautions 3. Tools and Parts Required 4. Specifications 5. Disassembly Procedures 6. Component Replacement 7. Common Issues and Solutions 8. Error Codes 9. Maintenance and Cleaning 10. Regulatory Information 11. Troubleshooting Guide

Features at a Glance

Key components: Stainless steel interior, multiple spray arms, adjustable upper rack, silverware basket, control panel, heating element, pump assembly, and door latch mechanism.

Feature	Description
Control Panel	Electronic touch controls with LED display
Wash Cycles	Normal, Heavy, Light, Rinse Only, Delay Start
Racks	Adjustable upper rack, fold-down tines
Spray Arms	Upper and lower rotating spray arms
Heating Element	Stainless steel heating element for drying
Pump Assembly	Circulation and drain pump system
Door Latch	Magnetic door switch and locking mechanism
Filter System	Self-cleaning filter and food disposer
Child Lock	Control panel lock feature
Energy Rating	ENERGY STAR certified

Safety Precautions

Before attempting any repairs, ensure dishwasher is unplugged and water supply is turned off.

Disconnect power: Unplug from electrical outlet or turn off circuit breaker.
Shut off water supply: Turn water valve to closed position.
Drain water: Place towel under unit and open drain valve if accessible.
Use proper tools: Insulated tools recommended for electrical work.

WARNING! Risk of electric shock and water damage. Always disconnect power and water before servicing.

Tools and Parts Required

Basic tools needed for most repairs.

Screwdrivers: Phillips and flathead set
Pliers: Needle-nose and channel lock
Multimeter: For electrical testing
Nut drivers: Various sizes
Putty knife: For panel removal
Bucket and towels: For water containment

CAUTION! Use only LG genuine replacement parts for optimal performance and safety.

Specifications

Model: LDS4821ST
Type: Built-in Dishwasher
Width: 24 inches
Capacity: 14 place settings
Color: Stainless Steel
Water Connection: Standard 1/2" NPT
Electrical: 120V, 60Hz, 15A
Water Pressure: 20-120 psi
Noise Level: 44 dBA
Warranty: 1 year parts and labor

Disassembly Procedures

Step-by-step disassembly for accessing internal components.

Remove lower kick plate: Remove screws and pull forward
Access door panel: Remove inner door screws and carefully separate
Remove control panel: Disconnect wiring harness and remove mounting screws
Access pump assembly: Remove lower rack and access panel
Remove spray arms: Twist counterclockwise to unlock

Tip: Take photos during disassembly for easier reassembly.

Component Replacement

Common component replacement procedures.

Heating Element: Disconnect power, remove lower access panel, disconnect wires, remove mounting nuts, install new element.

Pump Motor: Drain water, remove lower panel, disconnect hoses and wiring, remove mounting bolts, install new pump.

Door Latch: Remove inner door panel, disconnect wiring, remove screws, install new latch assembly.

Spray Arms: Remove lower rack, twist arms counterclockwise, lift out, install new arms.

Common Issues and Solutions

Dishwasher not starting: Check power supply, door latch, child lock.

No water entering: Check water supply valve, inlet valve, filter screen
Poor cleaning: Clean spray arms, check water temperature, use proper detergent
Not draining: Check drain hose, drain pump, food disposer
Leaking water: Inspect door seal, hose connections, pump seals
Unusual noise: Check for obstructions, worn pump bearings, loose spray arms

WARNING! Always test repairs with empty dishwasher before normal use.

Error Codes

Code	Description	Solution
IE	Water inlet error	Check water supply and inlet valve
OE	Drain error	Check drain hose and pump
FE	Water overflow	Check float switch and water level
LE	Leak detected	Inspect seals and connections
DE	Door switch error	Check door latch and switch

Maintenance and Cleaning

Monthly maintenance prevents common issues.

Clean filter: Remove and rinse under running water
Inspect spray arms: Clear any clogged holes
Check door seal: Wipe clean and inspect for damage
Run cleaning cycle: Use dishwasher cleaner monthly
Check drain hose: Ensure no kinks or obstructions

CAUTION! Do not use abrasive cleaners on stainless steel interior.

Regulatory Information

UL Listed: Complies with UL 749 standards. ENERGY STAR certified for energy efficiency. FCC Part 15: Class B digital device. Copyright © 2025 LG Electronics. For technical support, visit www.lg.com or contact 1-800-243-0000. Use only LG authorized parts for repairs to maintain warranty coverage.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
Dishwasher won't start	Power, door latch, child lock	Check power supply, ensure door closed properly, disable child lock
No water filling	Water supply, inlet valve	Check water valve is open, test inlet valve with multimeter
Water not draining	Drain hose, pump	Check drain hose for kinks, test drain pump operation
Poor cleaning results	Spray arms, water temp	Clean spray arm holes, ensure water heater set to 120°F minimum
Leaking water	Door seal, connections	Inspect door seal for damage, check all hose connections

Reset: Unplug for 5 minutes or turn off circuit breaker to reset control board.

Service: 1-800-243-0000; www.lg.com