Installation Guide
Tools Needed:
- Adjustable wrench
- Level
- Screwdrivers (flat and Phillips)
- Pliers
- Tape measure
- Vent duct clamps
Step-by-Step Installation
- Choose Installation Location: Select a location with proper ventilation, near plumbing and electrical connections on a solid, level floor.
- Remove Shipping Materials: Remove all shipping bolts and packaging materials from the combo unit.
- Connect Water Supply: Connect hot and cold water supply lines to the water inlet valves. Use only new, high-quality hoses.
- Install Venting System: Connect the dryer vent duct ensuring proper airflow and minimal bends for optimal performance.
- Connect Drain Hose: Route the drain hose into a standpipe or laundry tub with a high loop to prevent backflow.
- Electrical Connection: Connect to a properly grounded 240V outlet for dryer function and 120V for washer function.
- Level the Combo Unit: Adjust the leveling legs to ensure the unit is perfectly level from front to back and side to side.
- Test Run: Run both washer and dryer functions through complete cycles to check for leaks and proper operation.
Specifications
| Model Series | WM3900HWA |
| Type | All-in-One Washer Dryer Combo |
| Color | Graphite Steel / White |
| Washer Capacity | 4.5 cu. ft. |
| Dryer Capacity | 7.4 cu. ft. |
| Noise Level (Wash/Dry) | 55 dB / 65 dB |
| Control Type | Touch Controls with LCD Display |
| Energy Rating | ENERGY STAR® Certified |
| Water Consumption | 12.8 gallons per cycle |
| Power Requirements | 240V/120V, 60Hz, 30A |
| Dimensions (HxWxD) | 74 x 27 x 30 inches |
| Weight | 205 lbs |
| Max Spin Speed | 1300 RPM |
Warranty Information
- Full Warranty: 1 year parts and labor
- Motor Warranty: 10 years on Direct Drive Motor
- Dryer System Warranty: 5 years on dryer components
- Additional Coverage: Optional extended warranty available
For warranty service, contact LG Customer Service at 1-800-243-0000 or visit LG.com
Key Features
All-in-One Design
Combines washing and drying functions in a single unit, saving space and providing complete laundry solution in one machine.
ThinQ Technology
Smart connectivity allows remote control, cycle monitoring, and custom program downloads via smartphone app and voice assistants.
Direct Drive Motor
LG's innovative Direct Drive motor connects directly to the drum without belts, reducing noise and vibration while increasing reliability.
Sensor Dry System
Advanced moisture sensors detect when clothes are dry and automatically adjust drying time, preventing over-drying and saving energy.
Steam Technology
Steam refresh cycle reduces wrinkles and odors, while steam washing helps remove tough stains and allergens from fabrics.
TurboWash™ & TurboSteam™
Complete full loads in less time with accelerated washing and drying cycles without compromising cleaning performance.
Smart ThinQ Features
Remote Start
Start cycles remotely from your smartphone or voice assistant
Cycle Monitoring
Monitor cycle progress and receive completion alerts on your phone
Diagnostics
Smart diagnostics can identify issues and suggest solutions
Software Updates
Receive automatic software updates with new features and improvements
Energy Monitoring
Track energy and water usage through the ThinQ app
Custom Cycles
Download and create custom wash and dry cycles
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Unit won't start | Power issue, door not closed properly, child lock engaged | Check power supply, ensure door is latched, disable child lock |
| Clothes not drying properly | Overloading, lint filter clogged, vent obstruction | Reduce load size, clean lint filter, check vent system |
| Water not draining | Drain hose clogged or kinked, pump filter blocked | Check drain hose for obstructions, clean pump filter |
| Leaking water | Door not sealed, overfilling, loose water connections | Check door seal, ensure proper detergent amount, check connections |
| Unusual noises during drying | Foreign objects in drum, blower wheel obstruction | Check for foreign objects, inspect blower wheel |
| Error codes displayed | Various system malfunctions | Refer to error code section in manual, contact service if persistent |
Common Error Codes
- IE: Water supply issue - Check water supply and inlet valve
- OE: Drain issue - Check drain hose and pump
- FE: Flooding detected - Check for leaks and water supply
- LE: Motor issue - Contact service center
- dE: Door not closed properly - Ensure door is fully closed
- tE: Temperature sensor error - Contact service center
- HE: Heater error - Check dryer heating system
Manual Downloads
Current ThinQ Combo Models
WM3900HWA
4.5 cu. ft. ThinQ Combo
WM4000HBA
4.5 cu. ft. Black Combo
WM3900HCA
4.5 cu. ft. Graphite Combo
WM3488HW
Compact ThinQ Combo
Popular Previous Models
WM3997HWA
Previous Gen ThinQ Combo
WM3998HWA
Steam ThinQ Combo
WM3455HW
Compact Washer Dryer
WM3477HWA
Mid-Size ThinQ Combo