Direct answer
For the LG WashCombo WM6998HBA, treat standing water as a drain-path problem until the pump, filter, hose and household drain are separated. First, cancel the cycle, run Drain/Spin and listen for the pump.
What this covers
- LG WashCombo WM6998HBA (WM6998HBA)
- All-in-one heat-pump washer/dryer; determine whether the fault occurs during wash, drain, spin or dry.
- The specific fault this record addresses: will not drain or stops with water inside
What it does not cover
- ×The same symptom on a different LG product line, which has its own record and its own cited source
- ×An on-screen error code whose meaning has not been checked against this exact model's manual
- ×Live electrical, gas, sealed-system, internal battery-cell or structural repair — a technician boundary, not a self-service step
Differential
What actually causes this, and how to tell them apart
These are ordered by how often each one is the answer, not by how easy it is to try. The point of the middle column is that two causes producing the same headline symptom rarely produce the same detail — that detail is what tells you which one you have before you change anything.
- 1
The drain pump filter is clogged
What separates it The pump audibly runs but no water moves, or drains extremely slowly. Coins, hair clips, lint and small fabric items collect here over months and this is the single most common cause on a front-load machine.
How to confirm Front-load washers have an owner-accessible drain pump filter behind a small door at the bottom front of the cabinet. Open it over a shallow pan and towels — it will release standing water first, often a gallon or more.
- 2
An object is jamming the drain pump impeller
What separates it The pump makes a humming or buzzing sound without the normal water-movement noise, or makes a rattling sound as something strikes the impeller.
How to confirm On a machine with an accessible filter, the impeller is usually visible and turnable by hand once the filter is out and power is disconnected. On a top-load washer without an owner-accessible filter, this is a service diagnosis.
- 3
The drain hose is kinked, or pushed too far down the standpipe
What separates it Water drains and then partially returns, or the tub refills on its own after draining. A drain hose inserted too deep into the standpipe creates a siphon that pulls water back out of the machine.
How to confirm Check the hose for kinks behind the machine, and confirm the insertion depth and the standpipe height against the manual's stated range — both a too-low and a too-high standpipe cause drain faults.
- 4
The household drain or standpipe itself is restricted
What separates it The washer drains but the standpipe backs up and overflows, or a nearby sink gurgles or backs up when the washer drains.
How to confirm This is a plumbing problem rather than an appliance one — the tell is water backing up outside the machine rather than sitting inside it.
- 5
Excess suds are suppressing the drain cycle
What separates it The machine reports a drain problem after a load with heavy detergent, and foam is visible through the door or in the tub.
How to confirm See the suds-foam symptom — many machines pause draining and run extra rinses when they detect foam, which presents as a drain fault.
- 6
The drain pump has failed electrically
What separates it No pump sound at all during a Drain/Spin cycle — not a hum, not a rattle, silence where a pump should be audible.
How to confirm This is the conclusion once the filter is confirmed clear and the hose routing is correct.
Before you touch a setting
Record this first — changing settings destroys the evidence
Every item below stops existing the moment a reset, re-pair or settings change is made. Written down first, they are what separates the causes above; recovered afterwards, they are guesswork.
- Whether the pump makes any sound at all during a Drain/Spin cycle — a hum with no water movement, a rattle, or complete silence are three different faults.
- Whether water backs up outside the machine at the standpipe (a plumbing problem) or simply sits inside the tub (an appliance problem).
- Whether the tub drains and then refills on its own, which points specifically at drain-hose siphoning rather than a blockage.
- How much detergent was used on the affected load, since heavy suds can trigger a drain fault on a machine with a working pump.
Cancel the cycle and run Drain/Spin, listening for the pump
ReversibleThis separates a pump that is not running at all from one that is running against a blockage.
Clean the drain pump filter over a pan and towels
ReversibleIt is behind a small access door at the bottom front of the cabinet, and it will release standing water before it comes free — have more towels than you think you need.
Check the drain hose for kinks and confirm the standpipe height and insertion depth
ReversibleA hose pushed too far into the standpipe siphons water back out; the manual states both a minimum and a maximum standpipe height.
Arrange service for a silent or jammed pump once the filter and hose are confirmed clear
ReversibleOn a top-load machine with no owner-accessible filter, a pump problem is a service call rather than a maintenance task.
Run a short rinse and drain with no laundry to confirm
ReversibleConfirms the full path is clear before trusting it with a real load.
Model-specific
What is true of this model and not of its siblings
Generic advice for the product line fails here. Each item below is a property of this specific model family that changes which of the steps above apply to you.
- Model scope
- WM6998HBA. All-in-one heat-pump washer/dryer; determine whether the fault occurs during wash, drain, spin or dry.
- Type — all-in-one washer + ventless heat-pump DRYER
- This is not just a washer: the WashCombo washes AND dries in one drum, with a VENTLESS heat-pump dryer — no exhaust duct. So a 'not drying' complaint is a heat-pump and its condensate/filter question, not a vent, and clothes come out warm/damp-free rather than hot. Diagnose whether the fault is in the wash, drain, spin or dry stage first.
- Ventless drying implications
- Because it condenses moisture instead of venting it, the heat-pump has a lint filter AND a condenser/drain path that both need cleaning; a gradually poorer dry is usually a clogged filter or condenser, not a failed heater. It also dries at lower temperatures, so a full dry takes longer than a vented dryer — that is normal.
- Motor & smart
- Direct Drive inverter motor (no belt) and ThinQ Wi-Fi. Front-load door gasket care still applies for odour.
- Symptom boundary
- This record covers LG WashCombo WM6998HBA when it will not drain or stops with water inside. A different symptom on the same hardware, or this symptom on a different LG product line, has its own record with its own causes and its own cited source.
Stop boundary
When this stops being a self-service repair
Continuing past any one of these costs more than the repair saves — in safety, in warranty, or in evidence a technician needs.
- !Stop for wastewater backing up out of the standpipe or a nearby drain — that is a household plumbing problem and continuing to run the washer will flood the floor.
- !Broken glass in the filter housing, a burning smell from the pump, or water reaching wiring or an outlet means stop and disconnect power before anything else.
Evidence ledger
Sources behind this answer
Visible sources support the visible claims. Home Product Support records the publisher, the fact used and the review date; community reports can suggest an issue but do not become a published fact on their own.
Where the manufacturer's article stops. LG publishes this as "LG Washer - Why Isn't My Washer Draining". Directly addresses a cycle ending or stalling with water still in the drum. What that article does not carry is the model boundary — it is written for a product line, and WM6998HBA is the scope applied here. Where a control label, terminal, indicator pattern or reset sequence differs on your unit, the manual for that exact model is the authority, not this page and not the article.
Exact questions
Common follow-ups
My LG WashCombo isn't drying clothes fully.+
The WashCombo is a ventless heat-pump dryer, so 'not drying' is almost always a maintenance issue in that system, not a broken heater. Clean the lint filter every load and clean the condenser/heat-exchanger and its drain per the manual — a clogged filter or condenser is the top cause. Also avoid overloading (drying needs room to tumble) and remember heat-pump drying runs at lower heat, so it legitimately takes longer than a vented dryer.
There's still water in the drum and the pump is humming but nothing happens.+
A hum with no water movement points to a clogged filter or a jammed pump impeller rather than a failed pump. On a front-load washer, open the drain pump filter behind the small door at the bottom front of the cabinet — over a pan and towels, because it will release the standing water first.
The washer drains but then water comes back into the drum.+
That is drain-hose siphoning, not a pump fault. The hose is likely pushed too far down the standpipe, which lets it pull water back out of the machine. Check the insertion depth and standpipe height against the manual's stated range.
Where is the drain filter on a top-load washer?+
Most top-load washers have no owner-accessible drain filter at all — that is a front-load feature. On a top-loader, a confirmed drain blockage past the hose is normally a service call rather than something to clean out yourself.
Does this answer apply to every LG model?+
No. It is scoped to WM6998HBA. All-in-one heat-pump washer/dryer; determine whether the fault occurs during wash, drain, spin or dry.
What should I record before troubleshooting not draining or water left or drain pump?+
Record the complete model identifier, exact message or indicator, software/firmware where visible, the operating stage and what still works.
Why is a factory reset not the first step?+
A reset can erase accounts, networks, maps, schedules or preferences without distinguishing not draining, water left, drain pump. The ordered checks preserve that evidence.
When should I stop and use qualified service?+
Stop for wastewater backup, glass, burning odor or water near wiring.
Answer for the exact device and software version shown above.