LG Dishwasher LDS4821ST Service Manual

The LG LDS4821ST is a 24-inch built-in dishwasher featuring TrueSteam technology, QuadWash system with multi-motion arms, LoDecibel quiet operation, EasyRack Plus adjustable upper rack, SmartThinQ technology for Wi-Fi connectivity, stainless steel tub, multiple wash cycles, and advanced drying system. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Connecting Utilities 7. Operating Procedures 8. Maintenance Features 9. Care & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Control panel with digital display, QuadWash spray arms, TrueSteam generator, filter system, racks, and SmartThinQ module.

FeatureDescription
QuadWash SystemFour multi-motion spray arms for thorough cleaning
TrueSteam TechnologySteam cleaning for sanitization and better drying
LoDecibel OperationQuiet performance at 44 dBA
EasyRack PlusAdjustable upper rack with fold-down tines
SmartThinQWi-Fi connectivity for remote control and monitoring
Stainless Steel TubDurable and resistant to stains and odors
Power CordStandard 120V connection
Water Inlet ValveConnects to household water supply
Drain HoseFor wastewater removal
Control PanelTouch controls with cycle selection and options

Installation

Unpack and inspect contents. Ensure proper under-counter space.

  1. Connect water supply: Attach water inlet hose to hot water line with proper fittings.
  2. Connect drain hose: Route to sink drain or garbage disposal with air gap.
  3. Electrical connection: Plug into dedicated 120V grounded outlet.
  4. Level the unit: Adjust leveling legs for proper alignment.
  5. Secure to counter: Use mounting brackets if required.

WARNING! Ensure water connections are tight to prevent leaks. Use only dedicated electrical circuit.

First-Time Setup

Power on dishwasher; follow initial setup procedure.

  1. Remove shipping materials: Take out all tape and protective covers.
  2. Run initial cycle: Use Clean cycle without dishes to flush system.
  3. Set preferences: Configure default settings via control panel.
  4. Connect SmartThinQ: Download app and connect to home Wi-Fi network.
  5. Load test dishes: Verify proper operation with sample load.

CAUTION! Do not operate without removing all shipping materials. Ensure proper water flow before use.

Specifications

Controls and Settings

Access controls via front panel or SmartThinQ app. Front Panel: POWER, CYCLE SELECTION, OPTIONS, START/PAUSE.

Cycle Options: Normal, Heavy, Light, Rinse Only, Speed Wash, Sanitary, Crystal/Glass. Options: Hi-Temp Wash, Sani Rinse, Delay Start, Lock Controls, Child Lock.

Settings: Default cycle selection, sound volume, indicator lights, Wi-Fi connection status. SmartThinQ: Remote start/stop, cycle monitoring, diagnostics, usage reports.

Connecting Utilities

Water Supply: Hot water line connection. Drain: Hose to sink drain. Electrical: Standard outlet.

  1. Turn off water supply before connecting hoses.
  2. Ensure drain hose has proper loop to prevent backflow.
  3. Verify electrical outlet is grounded and dedicated.
  4. Check for leaks after initial connection.

Tip: Use thread seal tape on water connections. Ensure drain hose is not kinked.

Operating Procedures

Supports various dish types and soil levels.

  1. Load dishes: Arrange properly in racks, avoid blocking spray arms.
  2. Add detergent: Use recommended dishwasher detergent in dispenser.
  3. Select cycle: Choose appropriate cycle for load type.
  4. Add options: Select additional features like Hi-Temp or Sani Rinse.
  5. Start cycle: Press START; unit will begin operation.
  6. Monitor progress: Check status lights or SmartThinQ app.
  7. Unload: Wait for cycle complete signal; remove dishes when cool.

WARNING! Do not use regular dish soap. Load sharp knives pointing down. Remove large food particles first.

Maintenance Features

Filter Cleaning: Remove and clean filter monthly. Rack Adjustment: EasyRack Plus allows height adjustment. Self-Clean Cycle: Use to clean interior. Smart Diagnostics: Built-in error code system.

Care & Cleaning

Unplug before cleaning. Wipe exterior with damp cloth. Clean filter regularly. Run monthly cleaning cycle with dishwasher cleaner.

CAUTION! Do not use abrasive cleaners. Keep control panel dry. Clean spray arms periodically.

Regulatory Information

UL Listed: Complies with UL 749 standards. Energy Star Certified: Meets energy efficiency guidelines. FCC Part 15: Class B digital device. Copyright © 2023 LG Electronics; all rights reserved. For support, visit www.lg.com or contact 1-800-243-0000.

Troubleshooting

SymptomPossible CauseCorrective Action
Dishwasher won't startPower/door latchCheck power connection; ensure door closed properly; reset circuit breaker.
Poor cleaning resultsSpray arms/filterClean spray arms; check filter for debris; verify proper detergent use.
Water not drainingDrain hose/clogCheck drain hose for kinks; clean filter; verify drain pump operation.
Error codes displayedSystem faultsRefer to error code chart in manual; run SmartThinQ diagnostics.
Leaking waterSeals/connectionsCheck door seal; verify hose connections; inspect tub for cracks.

Reset: Unplug for 5 minutes or use reset function in settings.

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

LG Dishwasher LDS4821ST Service Manual © - All Rights Reserved 2025