LG Washing Machine Error Code SUD

Reviewed by the ApplianceErrors Editorial Team · Verified against manufacturer service documentation · Last verified: July 19, 2026

✓ Low Severity 🔧 Easy DIY Also shown as: SD

Excess suds detected — too much foam in the tub

The most common cause of the SUD error on a LG washing machine is too much detergent (~45% of cases); start with: let the cycle run.

💰 DIY cost: $0–$0 👨‍🔧 Pro cost: $0–$150

LG Washing Machine error code SUD on the display panel — How the SUD code appears on a LG washing machine display

What Does Error Code SUD Mean on a LG Washing Machine?

Excess suds detected — too much foam in the tub.

During drain and spin, the control monitors foam through pressure and motor feedback. When excess suds prevent the tub from draining or reaching spin speed, the board displays SUD (or SD) and injects extra rinses plus a foam-reduction routine to dissolve the foam before continuing. Unlike drain codes like OE, which flag a blocked pump or hose, or IE fill faults, SUD points to a detergent problem rather than a mechanical or sensor failure, and clears once foam subsides.

Models affected: Front-load and high-efficiency top-load LG washers, including models such as WM3900HWA, WM4000HBA, WM4500HBA, WM8100HVA, WM3400CW, WT7300CW, and WT7900HBA

What owners report: Owners commonly report SUD appearing mid-cycle after switching detergents or overfilling the dispenser, which stretches wash time considerably. Non-HE detergent, pods, and homes with soft water seem to trigger it most often; cutting detergent to a teaspoon or two and running an empty rinse usually resolves it.

What Causes Error Code SUD?

Here are the most common causes in order of frequency. Start with the most likely cause before moving to the next:

1

Too much detergent 45% of cases
2

Non-HE detergent used 35% of cases
3

Soft water amplifying suds 15% of cases
4

Drain restriction trapping foam 5% of cases

How to Fix LG Washing Machine Error Code SUD

🔧 Easy DIY Est. time: 10–20 min

⚡ Safety first: Unplug the appliance before opening any panels or touching internal components.

1

Let the cycle run

The washer will add rinses to clear the foam — this can take 30+ minutes. Don't interrupt it.
2

Use less HE detergent

Switch to HE detergent and use only 1–2 teaspoons for a normal load. Most people use far too much.

🔩 HE detergent
3

Run a Tub Clean / rinse cycle

Run an empty Tub Clean cycle to flush residual detergent from the system.

How to Reset Error Code SUD

Wait for the suds-reduction routine to finish, then restart. Reduce detergent next load.

Note: If the error returns after resetting, the underlying issue has not been resolved. Work through the fix steps above.

Full LG washer reset guide → Enter diagnostic mode →

Did this guide fix your appliance?

When to Call a Professional

SUD is almost never a hardware fault. Call a pro only if it appears with correct HE detergent and a clear drain.

Average professional repair cost for this issue: $0–$150

Related Error Codes

Water inlet error — water not filling within expected time

⚠ Medium Severity

Drainage error — water not draining within expected time

⚠ High Severity

Same Code on Other Brands

Error code SUD appears on these other brands too. See every brand that shows SUD →

Samsung Washing Machine SUD

Excessive suds detected

Whirlpool Washing Machine SUD

Excessive suds detected — too much detergent

KitchenAid Washing Machine 5D

Excessive suds detected

Maytag Washing Machine SUD

Excessive suds — too much detergent

Find Replacement Parts

Use these links to find the exact replacement parts for your LG Washing Machine:

🔩

Search PartSelect

LG Washing Machine repair parts

🔧

Search RepairClinic

Step-by-step video guides

External links — ApplianceErrors.com is not affiliated with these retailers.

More LG Washing Machine Error Codes

UE Unbalanced load — cannot complete spin cycle LE Motor locked — hall sensor or stator fault dE Door open or door lock failure tCL Tub clean reminder — drum needs cleaning FE Water overflow error — drum overfilling HE Heater error — water heater circuit fault

Frequently Asked Questions

Can I keep using my LG Washing Machine when error SUD appears? +

Usually yes — SUD is a low-severity detergent notice that rarely stops the washing machine from working, but clearing the underlying cause prevents it from escalating.

What most commonly causes SUD on a LG Washing Machine? +

Across reported LG washing machine repairs, the most frequent is too much detergent (45% of cases), non-HE detergent used (35%), then soft water amplifying suds (15%). Check them in that order before replacing any parts.

SUD keeps coming back after a reset — what should I check next? +

A reset only clears the stored SUD fault; if it returns, the detergent problem is still present. Move on to the physical checks — let the cycle run, then use less HE detergent — since the code will reappear until the root cause is resolved. This is a beginner-friendly job needing only basic hand tools.

How much does it cost to fix LG Washing Machine error SUD? +

A DIY repair typically runs $0–$0 in parts, versus $0–$150 for a professional service call. Expect the work to take about 10–20 minutes.

Which LG Washing Machine models show error SUD? +

SUD is documented on Front-load and high-efficiency top-load LG washers, including models such as WM3900HWA, WM4000HBA, WM4500HBA, WM8100HVA, WM3400CW, WT7300CW, and WT7900HBA. Other units sharing the same control platform can display it too, so the fixes here generally transfer across the series.

Sources & References

• LG Support — Help Library — official manufacturer documentation
• Our editorial & verification policy

Content verified against manufacturer service documentation. Last verified: July 19, 2026.

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