To enter LG dryer diagnostic mode: With dryer in standby, press and hold MORE TIME + LESS TIME, then press POWER while holding both. Press START/PAUSE to cycle through component tests. Unplug for 1 minute after exiting diagnostic mode to reset normal operation.
LG dryers include a built-in diagnostic mode that allows you to test individual components and verify proper installation. This is the same test mode technicians use for troubleshooting.
Standard Diagnostic Mode Entry
This method works on most LG dryer models:
- Dryer must be in standby mode (plugged in, display off)
- Press and hold MORE TIME + LESS TIME simultaneously
- While holding both buttons, press POWER
- Display indicates diagnostic mode is active
- Press START/PAUSE to cycle through tests
- Press POWER to exit
- Unplug for 1 minute after using diagnostic mode
Button Combinations by Model Series
Different model series may use different button combinations:
| Model Series | Button Combination |
|---|---|
| DLEX/DLGX (most models) | MORE TIME + LESS TIME + POWER |
| DLE3500/DLG3501 | TEMP + SIGNAL |
| DLE3400/DLG3401 | TEMP + WRINKLE CARE |
| DLE7100/DLG7101 | TEMP + WRINKLE CARE |
| DLE3600/DLG3601 | TEMP + ENERGY SAVER |
| DLEX8900/DLGX8901 | MORE TIME + DAMP DRY SIGNAL |
| WashTower (WKEX/WKGX) | SIGNAL + ENERGY SAVER (hold 3 sec) |
If the standard method doesn’t work, try your model’s specific combination.
What Diagnostic Mode Tests
When you cycle through diagnostic mode with START/PAUSE, it tests:
| Test | What It Checks |
|---|---|
| Motor | Drum rotation, motor operation |
| Heating | Element (electric) or igniter (gas) |
| Thermistors | Temperature sensor readings |
| Door switch | Door open/closed detection |
| FlowSense | Exhaust airflow sensor |
| Moisture sensor | Humidity bars inside drum |
| Control board | Internal communication |
Each test displays a code or activates the component being tested.
Installation Test (Duct Check)
The Installation Test specifically verifies your vent system is adequate. This is useful after installing a new dryer or cleaning vents.
How to Run Installation Test
- Empty the drum — No clothes or items
- Ensure dryer is cool (not recently run)
- Press POWER to turn on
- Immediately (within 1 second) press designated button pair:
- Most models: TEMP + SIGNAL
- Or: MORE TIME + LESS TIME
- Display shows “InS” (Installation) when activated
- Press START/PAUSE to begin test
- Test runs approximately 2 minutes with heat
Interpreting Results
| Result | Meaning |
|---|---|
| No FlowSense LED | Exhaust system adequate |
| FlowSense LED lit | Airflow restricted—clean or modify vent |
If the FlowSense indicator illuminates during the Installation Test, your vent system needs attention before normal use.
Run the Installation Test after any vent cleaning to verify you’ve restored adequate airflow. It’s also useful after moving a dryer to a new location or changing vent routing.
Reading Diagnostic Codes
During diagnostic tests, the display shows codes indicating:
- Test number — Which test is running
- Sensor values — Temperature readings, moisture levels
- Error history — Previous error codes stored in memory
The exact codes vary by model. Refer to your service manual for specific interpretations.
Error History Access
Some LG dryers store a history of recent error codes. To access:
- Enter diagnostic mode
- Cycle to the error history test
- Display shows recent codes in sequence
- Write down codes for troubleshooting
This helps identify intermittent issues that may not be active when you check.
Exiting Diagnostic Mode
Important: After using diagnostic mode:
- Press POWER to exit
- Unplug the dryer for 1 minute
- Plug back in
This clears any test states and restores normal operation. Skipping the unplug step may cause unusual behavior on the next cycle.
Safety Notes
- Never reach into the drum during motor or heating tests
- Drum will spin and heating element will activate during tests
- Keep the door closed during automated tests
- Gas dryers: Igniter and burner will fire during heating test
- Don’t run heating tests for extended periods
When Diagnostic Mode Helps
Use diagnostic mode to:
- Verify heating works after nP or tE errors
- Test door switch after dE errors
- Check FlowSense after cleaning vents
- Identify failing components before they completely fail
- Confirm repairs after replacing parts
Model Coverage
Diagnostic mode is available on:
Electric (DLE/DLEX): All models with digital displays
Gas (DLG/DLGX): All models with digital displays
Heat Pump (DLHC): All models
WashTower: All models (access through dryer control panel)
Budget models without digital displays may have different (or no) diagnostic access.
Professional vs DIY Use
Diagnostic mode provides valuable information, but interpreting results often requires experience:
| User Level | Useful For |
|---|---|
| Homeowner | Installation test, basic motor/heat verification |
| Advanced DIY | Sensor readings, error history |
| Technician | Full component testing, calibration |
If diagnostic mode reveals a problem but you’re unsure how to fix it, the information is still valuable to share with a technician.
Sources
For official LG support: