LG Washer SUD Error Code — What It Means
The SUD error code means your LG washer has detected excessive suds or foam in the drum. This is a protective control state, not a failure of a component. When the washer senses too much foam, it automatically enters a suds-reducing mode that can add about 2 hours to your cycle. If heavy suds appear during the spin phase, the machine may stop spinning to prevent leaks. The code is almost always triggered by detergent practices rather than a mechanical fault.
Common Causes
- Too much detergent Using more detergent than the load and water conditions require creates excess suds that trigger the code.
- Non-HE detergent in an HE washer Regular detergent produces far more foam than high-efficiency washers can handle.
- Soft water conditions Soft water increases sudsing activity, so the same detergent dose will produce more foam.
- Residue buildup in the drum Repeated oversudsing leaves detergent residue inside the tub that continues to foam in later cycles.
- Restricted drain path A clogged drain pump filter or kinked drain hose can slow drainage and allow suds to accumulate.
Step-by-Step Fix
- Let the cycle finish. Allow the washer to complete its suds-reducing routine, which can take up to 2 hours longer than normal.
- Unplug the washer for 10 seconds, then restore power to clear the control board and reset the cycle if you want to try again immediately.
- Switch to HE detergent and cut your dose in half for the next load, especially if you have soft water or a small load.
- Run a tub-clean cycle or an empty hot-water cycle with no detergent to flush out any residue buildup left from previous oversudsing.
- Check the drain pump filter at the front lower panel (most models), remove any debris, and confirm water drains freely when you test a rinse cycle.
- Inspect the drain hose for kinks, clogs, or improper installation that might restrict water flow and trap suds in the drum.
- Test with a minimal-detergent load after cleaning and drainage checks to confirm the error does not return under correct detergent use.
Parts Often Needed
| Part | Notes |
|---|---|
| HE laundry detergent | Amazon | High-efficiency formula required for front-load and top-load HE washers to prevent excess suds. |
| Drain pump or drain pump filter | Amazon | Replace the pump or clean the filter if drainage is restricted and the error persists after detergent correction. |
| Drain hose | Amazon | Replace if the hose is kinked, cracked, or internally clogged and cannot be cleared. |
When to Call a Pro
Call a technician if the SUD error returns repeatedly after you have switched to HE detergent, reduced your dose, run a cleaning cycle, and verified that the drain path is clear. Persistent false SUD codes after proper detergent practice may indicate a control board issue or a sensor fault that requires diagnostic tools and access to your model’s service manual. If the washer stops mid-cycle every time and will not advance even with minimal detergent, professional evaluation is the next step.