LG Washer SUD Error Code: Meaning, Causes & Fix

Suds detected — the washer has detected too many suds and is running its suds-reducing cycle (displayed as Sd or SUD depending on the panel).

LG's front-load manuals describe the behaviour identically across generations: if the washing machine detects too many suds, it displays this code and adds a Suds Reducing cycle — which adds about two hours to the cycle time — and if too many suds are detected during spinning, the washing machine stops to help prevent leaking. Read that carefully: SUD is the washer managing a detergent condition, not reporting a failed part. The two causes LG's troubleshooting tables name for excessive sudsing are too much detergent and incorrect detergent: HE detergents are formulated specifically for high-efficiency washers and contain suds-reducing agents, and LG's instruction is to use only detergent with the HE logo, in the amount the detergent manufacturer recommends. LG publishes no tablespoon figure of its own — dose guidance on this page follows the detergent maker's label and the manual's Detergent Use section, deliberately.

What causes the SUD code on a LG washer?

Too much detergent

LG's first named cause. In a low-water HE wash, a generous pour — or a double dose 'for a dirty load' — produces foam the machine then has to spend up to two hours reducing.

Incorrect detergent

LG's second named cause: detergent without the HE logo is formulated to foam in a full tub of water. In an HE machine that foam overwhelms rinsing and spinning alike, and no dose discipline fully compensates for the wrong formulation.

Detergent residue already in the machine

LG's excessive-sudsing troubleshooting pairs sudsing with detergent residue as a continuing issue: residue from earlier overdosing re-foams into later cycles, which is why a corrected dose can still meet one or two SUD displays while the machine clears itself out. LG's documented answer to the residue case is an extra rinse.

Checks to run before you replace anything

1. Look through the door glass: visible foam standing in the tub confirms the code is reporting suds, not malfunctioning.
2. Check the detergent itself before the machine: does the pack carry the HE logo, and was the dose the detergent manufacturer's recommended amount for the load — not a full cap by habit?
3. Ask whether anything changed: a new detergent, a switch to a concentrated format dosed like the old one, or a helper product added to the wash. SUD that starts the week a product changed is a dosing story with a date on it.

How to fix the SUD error code

1. Let the suds-reducing cycle finish. It is long — about two hours added, per LG's manuals — because dissolving foam cannot be hurried, and the spin stop is the machine preventing a leak, not failing. Do not force the door against a tub full of foam.
2. If sudsing or detergent residue continues to be an issue after the dose is corrected, add an Extra Rinse — LG's documented remedy for the residue case.
3. Dose permanently by the detergent manufacturer's recommended amount and use only HE-logo detergent. That pair of habits is the whole prevention for this code.

The part that usually fails: None

A condition report, not a component fault. LG's manuals assign SUD no part and no service remedy; a machine that shows the code with no detergent in it at all has left the code's documented definition and belongs in a service conversation on that basis.

How to reset / clear the SUD code

SUD clears itself: the code stands while the suds-reducing cycle runs and goes when the foam falls. There is no button reset for it, and power-cycling a tub full of foam just restarts the same management problem on the next cycle.

LG's standard reset is a power cycle: press Power off, unplug the washer for about 5 minutes, then — with the machine still unplugged — press and hold the Start/Pause button for 5 seconds to drain residual charge from the board. Plug back in and run a test cycle. There is no hidden reset button on LG washers; any code that reappears after this procedure is an active fault the control is still detecting, not a glitch that needs a deeper reset.

Why does the SUD code keep coming back?

SUD on every load with the dose unchanged is the dose or the detergent restating itself. SUD that fades over several corrected loads was the residue clearing. SUD that persists indefinitely on a correct HE dose, in a machine that has been rinsed clean, no longer matches anything LG documents for this code — that is the point to stop re-dosing experiments and book service.

How to stop SUD coming back

• Too much detergent: LG's first named cause. In a low-water HE wash, a generous pour — or a double dose 'for a dirty load' — produces foam the machine then has to spend up to two hours reducing.
• Incorrect detergent: LG's second named cause: detergent without the HE logo is formulated to foam in a full tub of water. In an HE machine that foam overwhelms rinsing and spinning alike, and no dose discipline fully compensates for the wrong formulation.
• Detergent residue already in the machine: LG's excessive-sudsing troubleshooting pairs sudsing with detergent residue as a continuing issue: residue from earlier overdosing re-foams into later cycles, which is why a corrected dose can still meet one or two SUD displays while the machine clears itself out. LG's documented answer to the residue case is an extra rinse.

Retrieving stored fault codes on LG washers

LG front-loaders have a test mode used by technicians: with the machine off, a specific three-button combination (commonly Soil Level + Spin Speed + Power held in sequence on many models, and a button-pair hold on others) steps the machine through fill, wash, drain, spin and heater tests while the display shows stored error history. The exact combination differs by model year, so technicians read it from the service manual for the model; if you enter a mode where the tub starts filling or the motor jogs, that is the test mode working — press Power twice to exit.

Other LG washer error codes

See the full list on the LG Washer error codes hub.

Codes SUD gets confused with

FE — Overflow error — the water level is too high (LG's manuals: 'Water level is too high due to a faulty water valve'; LG's top-load list: the washer has detected an overfilled tub). FE is LG's overfill code, the mirror of IE: too much water has been supplied to the tub.

AE — Two different LG faults share this code, by platform. On LG top-load washers AE is a rotation error: the gears responsible for rotating the drum cannot operate properly. On LG front-load washers (global/EU manuals) AE is a water leakage error: water leaks — call for service. AE is the LG washer code where reading a single meaning off the internet does real damage, because LG itself publishes two.

dE1 — Door error (variant 1) — the door is not closed properly (LG's own wording). The washer cannot confirm the door is fully shut, so it will not start or it pauses. LG splits its front-load door family by which step failed, and dE1 is the first step: the door is not closed properly.

tE — Temperature sensor error — LG's front-load manuals head this code 'Temperature Sensor Error' and give its cause, in one word pair, as a control error; LG's top-load list describes a problem with the temperature sensor inside the tub. tE is the code LG's documentation treats most tersely, and this page follows LG rather than the internet's expanded version of it.

Working from a symptom instead? Read our troubleshooting guide for this problem.

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Facts on this page were checked against manufacturer documentation: www.lg.com · www.lg.com · lg.com · www.lg.com