Sud
LG Washing Machine
Severity: MinorWhat Does This Error Mean?
The Sud error means your LG washer has detected too many suds (foam) inside the drum. Excess suds prevent the drum from spinning and rinsing properly. The washer pauses to let the suds settle before continuing.
Affected Models
- WM3900HWA
- WM4000HWA
- WM3500CW
- WM3700HWA
- Most LG front-load washers
Common Causes
- Too much detergent was used for the load size
- Regular (non-HE) detergent used in a high-efficiency (HE) washer
- Detergent residue has built up inside the drum over many cycles
- Low-quality or budget detergent that produces excessive foam
- Soft or very soft water causes detergent to lather more than usual
How to Fix It
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Do not open the door or add more water — let the washer pause and wait.
The washer will automatically add extra rinse cycles to clear the suds. This can take 20–30 extra minutes.
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Once the cycle finishes, check the detergent you are using.
LG front-load washers require HE (High Efficiency) detergent only. Look for the HE symbol on the bottle.
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Measure detergent carefully on your next wash.
Most people use 2–4 times more detergent than needed. For HE washers, use 1–2 tablespoons maximum.
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Run a Tub Clean cycle to remove detergent buildup from the drum.
Use the Tub Clean setting (or a hot empty cycle) monthly to prevent buildup.
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If you have very soft water, reduce detergent even further — soft water multiplies suds.
Try using half the already-reduced amount and see if suds improve.
When to Call a Professional
The Sud error almost never requires a technician — it is a user-level issue in nearly all cases. If the error persists after switching to the correct HE detergent and cleaning the drum, the suds sensor itself may be faulty. In that unlikely case, contact an LG technician.
Frequently Asked Questions
How long will the Sud error last?
The washer will automatically try to rinse away the suds. This can add 20–45 minutes to your cycle. Do not interrupt the cycle — let it complete on its own.
What detergent should I use in an LG front-load washer?
Always use detergent labeled HE (High Efficiency). Popular HE brands include Tide HE, Persil ProClean, and Seventh Generation. Regular detergent creates far too many suds for front-load washers.
My LG washer shows Sud every wash — is something wrong?
If it happens every cycle after switching to HE detergent and reducing the amount — there may be significant detergent buildup inside the drum and hoses. Run 3–4 consecutive Tub Clean cycles to flush the buildup out. The problem should resolve after thorough cleaning.