The Sd / SUD error code on an LG washer means the machine has detected too much foam inside the drum. The washer pauses automatically and attempts a self-clearing suds-reduction cycle. In most cases no repair is needed — simply wait for the machine to finish clearing the suds (up to 30 minutes), then switch to HE (High Efficiency) detergent and use the correct amount going forward. Recurring Sd errors despite correct detergent can point to a residue buildup in the drum or a faulty pressure/water level sensor.
What the Sd / SUD Code Means
The LG washer Sd (or SUD) error code is an excess suds alert. It appears when the washer's pressure sensor or optical foam detector registers an abnormally high foam level inside the drum during a wash or rinse cycle. To protect the machine — and to prevent soapy water from overflowing — LG's control board pauses the active cycle and launches an automatic suds-reduction routine.
During this self-clearing phase, the washer adds cold water, tumbles slowly without spinning, and waits for the foam to dissipate. The display may show Sd or SUD flashing for anywhere from a few minutes to half an hour. Do not unplug or restart the washer during this phase — let it complete on its own.
Unlike drain or motor errors, Sd is usually a user-correctable issue, not a mechanical fault. The most common trigger is using too much detergent, using non-HE detergent in an HE machine, or detergent residue that has built up inside the drum over time.
Common Causes — Most Likely First
How to Fix the Sd / SUD Error — Step by Step
Do not turn off the washer — let it self-clear first
When Sd or SUD appears, the washer has automatically paused and entered a suds-reduction routine. Leave it running. The machine will add water, tumble slowly, and wait for the foam to break down. This process can take up to 30 minutes. Once the suds clear, the machine will attempt to resume or complete the cycle on its own.
If the washer does not resume — run a Rinse + Spin cycle
If the washer finishes the self-clear routine but does not resume automatically, select a Rinse + Spin cycle to flush out any remaining suds and complete the laundry. Do not add any more detergent for this cycle.
Switch to HE detergent
Check the detergent you are currently using. If it does not carry the HE symbol (a small "he" inside a circle), switch to an HE-rated detergent. Using standard detergent in an LG washer is the single most common reason for repeat Sd errors.
Measure the correct detergent dose
Follow the detergent manufacturer's guidelines for HE machines — typically 1–2 tablespoons for a normal load. More detergent does not mean cleaner clothes; it means more suds and more rinse cycles. If you live in a soft-water area, use the lower end of the recommended range or reduce by 25%.
Clean the drum to remove detergent residue
If you've been over-dosing for a while, residue may have built up on the drum walls and door gasket. Run a Tub Clean cycle (or the hottest empty cycle available on your model) with a washer cleaner tablet or one cup of white vinegar in the drum. Repeat once a month going forward.
Clean the detergent dispenser drawer
Pull out the dispenser drawer and rinse it under warm water. Old detergent and fabric softener can cake inside the compartments and slowly release suds-causing residue into the drum during each wash. Clean the drawer cavity inside the machine as well.
Run a test cycle and monitor
Run a normal wash cycle with the correct HE detergent at the proper dose and a clean load of laundry. If Sd does not appear, the issue is resolved. If it comes back despite using HE detergent at the correct amount, proceed to the next step.
If Sd persists with correct detergent — the sensor may have failed
A water level sensor or pressure hose fault can cause false suds detections. This is a diagnosis-and-replacement job that requires accessing internal components. Contact a technician to test the pressure sensor and hose for faults before replacing parts.
When to Call a Technician
The Sd error is almost always resolved by switching to HE detergent and using the correct dose. Book a professional LG washer repair if:
- Sd returns repeatedly even though you are already using HE detergent at the recommended quantity
- You have completed multiple Tub Clean cycles but the error persists on every load
- The machine never exits the suds-reduction phase and the cycle never resumes on its own
- Sd appears simultaneously with another error code such as OE or IE, suggesting a sensor or control board issue
- You notice the washer overfilling or underfilling with water on normal cycles, pointing to a faulty pressure sensor that is also triggering false Sd alerts
Repair Cost Expectations
If You Fix It Yourself
Pressure Sensor Replacement
Sd Error Won't Clear? We'll Diagnose It Today.
Same-day appointments across Boston and MetroWest. Certified LG technicians, pressure sensors and control parts stocked on the truck, and a 90-day warranty on every repair.
Frequently Asked Questions
Is the Sd / SUD error dangerous? Will it damage my washer?
No. The Sd error is a protective pause, not a fault that causes damage. The washer stops itself specifically to prevent foam from overflowing or interfering with the spin cycle. As long as you let the machine complete its self-clearing routine rather than forcing a restart repeatedly, no harm is done to the appliance.
How long does the LG suds self-clearing routine take?
Typically between 5 and 30 minutes, depending on how much foam is present. The machine adds cold water, pauses, and tumbles slowly to break down the suds. Do not interrupt it. Once the foam level drops to an acceptable range, the washer will attempt to resume the cycle automatically.
Can I use any HE detergent, or does it need to be a specific brand for LG?
Any detergent carrying the HE symbol is suitable for LG washers. LG does not require a proprietary brand. Popular HE detergents include Tide HE, Persil ProClean, Gain HE, and most store-brand HE options. The key is the HE formulation — not the brand. Use the dosage marked for HE machines, which is usually the lower of the two recommended amounts on the cap.
Will resetting my LG washer fix the Sd error?
A reset clears the code from the display but does not remove the suds from the drum. If you restart the machine before the foam has dissipated, the sensor will detect it again and Sd will immediately come back. Let the self-clearing routine finish first, or run an empty Rinse + Spin cycle without adding detergent to flush out remaining foam before attempting another normal wash.
Why does my LG washer show Sd even though I use the right detergent and amount?
There are a few possibilities. First, check for residue buildup in the drum from prior over-dosing — even correct detergent use today can trigger Sd if old soap layers are dissolving. Run several Tub Clean cycles with a washer cleaning tablet to clear the residue. Second, if your water supply is unusually soft, reduce your detergent dose by 25–50% from the package recommendation. If neither applies, a faulty pressure sensor may be falsely detecting foam and will need professional diagnosis.
How often should I run a Tub Clean cycle to prevent Sd errors?
LG recommends running the Tub Clean cycle once a month. If you run large or heavily soiled loads frequently, every two to three weeks is reasonable. Keeping the drum clean of detergent residue is the most effective long-term prevention for Sd errors, in addition to using the correct HE detergent and dose.