Last Updated on October 4, 2026 by Umar Farooq
When a washing machine fills then drains, this is almost never an electrical fault. It is a straw.
If the drain hose sits too deep in the standpipe — or is sealed airtight around it — the hose stops being a drain and becomes a siphon. Water goes in at the top of the drum, finds a continuous column of water in the hose, and gravity pulls it straight back out. The machine is filling correctly. The drain pump is switched off. Physics is quietly emptying the drum behind its back, and the control board has no idea it is happening.
That is why nothing on the panel indicates a fault, and why replacing parts never helps.
The number that fixes it: don’t insert the drain hose more than about 4 inches into the standpipe.
The connection is meant to be loose. Air has to be able to get in around the hose to break the water column — that gap is not sloppy installation, it is the thing that stops your machine emptying itself.
Why a washing machine fills then drains, in order of likelihood
- The drain hose inserted too far into the standpipe. Past a few inches the air gap disappears and siphoning starts.
- An airtight seal around the hose — tape, a tight adapter, or anything closing off the gap. Same effect as inserting it too deep, and usually done deliberately by someone trying to stop the hose jumping out.
- The standpipe or drain point sitting too low relative to the machine, so gravity pulls water out.
- A hose that sags or dips below the drain connection anywhere along its run, creating a low trap that siphons.
- A hose extended too far past its elbow bracket, which also allows mould to spread inside the machine.
- A drain pump or valve that doesn’t seal shut between cycles.
- A pressure-sensing or control fault triggering an unintended drain. Genuinely last.
The five-minute fix
1. Pull the hose back out
Withdraw the drain hose so no more than about 4 inches sits inside the standpipe. This alone fixes most cases.
2. Break any seal
Remove tape, and don’t use a tight-fitting adapter that closes the gap. If the hose keeps jumping out, secure it with the elbow bracket and a loose tie — not by sealing it in.
3. Check the height
The drain point needs to be high enough that water cannot run downhill out of the tub. A common documented range is no lower than about 34 inches and no higher than about 96 inches from the floor.
4. Check the hose run
Follow the whole length. Any dip below the drain connection makes a trap that siphons. Support the hose so it rises steadily to the drain point.
5. Fit the elbow bracket properly
Keep the hose end within about 4 inches of the bracket — extended further and mould can spread back inside the machine.
Stop-use warning: Don’t run the machine while diagnosing this — you’ll pump water onto the floor. Turn off the supply valves before repositioning the hose, and check for leaks at every connection afterwards.
Where the siphon was, and what to do about it
| What you observed | What it means | Where to go next |
|---|---|---|
| Hose was inserted deep, fixed by pulling it back | Classic siphon — resolved | Nothing further |
| Hose taped or sealed at the standpipe | No air gap | Remove the seal |
| Drain point lower than the drum | Gravity drainage | Raise the drain point |
| Hose sags below the connection | Low trap siphoning | Support the run |
| Installation confirmed correct, still empties | Pump or valve not sealing | Service |
| Fills and stays, but never washes | Not this problem | Stuck on sensing |
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Samsung says 6 to 8 inches into the standpipe
- Samsung documents the insertion depth and warns that an airtight connection is what creates the siphon (Samsung, “Samsung — washer spins poorly”).
- Insert the hose 6 to 8 inches into the standpipe on Samsung’s guidance — enough to stay put, not enough to seal.
- If a drain code appears alongside this, check it against the code list (information and error codes).
LG: the elbow bracket, the 4-inch rule and mould
- LG warns against inserting the hose more than a few inches into the standpipe, since going deeper removes the air gap and creates exactly this condition.
- LG documents the connection method precisely: “Place the drain hose to the side that you want to use, push the spring side of the elbow hose firmly into the drain hole” (top load washer — how to install the drain hose).
- Keep the hose end within 4 inches of the elbow bracket — LG documents that extending further “could spread mold or microorganisms into the inside of the washer.”
- Height range: no lower than 34 inches, no higher than 96 inches (8 ft).
- If an
OEcode appears alongside, that is a drain fault rather than siphoning (LG washing machine — water not draining (OE error)).
Same physics on Whirlpool, Maytag, Amana and Kenmore 110
Same physics, same fix. Expect F8E1/Lo FL if the machine reports a low fill level because the water keeps leaving.
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Watch one fill and check the level five minutes later
- Start a cycle and watch the fill directly.
- Confirm the level rises and then stays while the wash begins.
- Check the drum again five minutes in — the level should be unchanged.
- Confirm the hose hasn’t slipped back into the standpipe.
- Check for leaks at the standpipe after the drain phase.
Water leaving an unplugged machine is a valve, not the hose
- Hose depth, seal, height and run all confirmed correct, and water still leaves during fill.
- Water drains from the drum while the machine sits idle and unplugged — that points at a pump or valve not sealing.
- An unexpected drain step runs immediately after fill even with correct installation.
FAQ
Why does the hose need to be loose in the standpipe?
Because air has to be able to enter and break the siphon. A tight or deep fit turns the hose into a straw.
It fills and stays but never starts washing. Different problem — see washing machine stuck on sensing.
It won’t drain at all instead. The opposite fault — see washing machine won’t drain.
How far into the standpipe should the hose go?
A few inches — around 4, and Samsung specifies 6 to 8 for its machines. Deep enough not to fall out, shallow enough to keep the air gap.
Can I tape the hose to the standpipe to stop it moving?
No. Tape seals the air gap and causes exactly this problem. Use the elbow bracket and a loose tie instead.
This started after a plumber worked on my drains. Very likely the hose was pushed deeper or sealed while they worked. Check the depth first — it takes ten seconds.
An OC or OE code shows during this. That’s overflow detection tripping, which suggests the level went too high before the drain response rather than pure siphoning. See Samsung washer OC or OE overflow error.
