The WM3998HBA is a conventional ventless condensing combo, not a stand-alone vented dryer. Its drying process needs cold water. A closed cold tap, reversed supplies or a load that cannot tumble freely deserves attention before assuming a failed heater.
Models covered
WM3998HBA conventional condensing combo. Excludes heat-pump WashCombo models and stand-alone LG dryers; their drying systems differ.
Wait for motion to stop and the door or lid to unlock. Water may be hot. Isolate power and follow the exact manual before any user filter maintenance. Never open a filter against a full drum, force a lock or bypass an interlock.
Compare the behavior
Match the documented control, cycle or feature before interpreting the result. The comparison below keeps normal model behavior separate from an unresolved fault.
| Observed state | Interpretation / next step |
|---|---|
| Cold water supply shut | Restore the documented supply before judging drying. |
| Damp finish intentionally selected | Reconsider finish selection, not heater parts. |
| Smaller suitable load still wet with correct supplies | Arrange diagnosis with cycle and code details. |
Model-specific checks
Trace the two paths used while drying
Moisture has to leave the laundry and the condensed water has to leave the appliance. Check the accessible cold supply is open and look for visibly crushed hoses. Record a drain or inlet code separately. Do not open the cabinet or pull an installed appliance into an unsafe position to reach a hidden connection.
Check what the controls promised
Compare the selected dry finish with the garment-care instructions. Damp Dry is not a promise of cupboard-dry clothing. Separate a normal damp-finish selection from a normal dry selection that consistently leaves the whole load wet.
Use a meaningful load comparison
When the washer is otherwise operating without a fault code, compare a smaller suitable load that has room to tumble. A full wash drum need not be a good drying load. Record whether the smaller load improves, whether the unit heats, and whether water drains; those are separate observations, not a parts diagnosis.
What to record next
The distinctive issue is the water-dependent condensing system. A generic “clean the dryer vent” answer misses the architecture of this exact appliance.
When to stop and get help
Only carry out maintenance permitted in your model’s manual. For service, note the full model number and suffix, displayed code, selected cycle and what happened during the checks. Leave internal wiring, gas components, pumps and safety devices to a qualified professional. A symptom alone does not identify a failed part.
Sources & references
- Conventional combo drying uses cold water to condense moisture. Water Taps
- Reversed supplies and restricted cold-water flow reduce drying performance. Water Taps; Inlet Filters and Hoses
Based on publicly available manuals, manufacturer support and the references listed here. We have not inspected or tested your appliance. Follow the instructions for your exact model; a guide cannot replace an in-person diagnosis.