Washer draining before it washes? Often it’s not the machine, it’s where the drain hose ends

Why water runs out while the washer is still filling

Water runs downhill. If the end of the drain hose is lower than the water level in the tub, or pushed deep into the standpipe and sealed there, the hose acts like a siphon: as soon as water reaches it, it flows out on its own and pulls the rest after it, even with the pump off. LG’s support page explains that the washer then senses too little water and keeps topping up, filling and draining over and over, and modern washers stop the cycle and show an error. That’s why many people search “washer won’t finish the cycle” for the same problem. Samsung says this siphoning can trigger a 4C or LC error on its washers.

Five things to check yourself before calling a technician

1. Where does the end of the hose sit?

   Samsung specifies the hose end between 60 and 90 cm above the floor, and says that below 60 cm water may drain out of the washer by siphoning. LG gives a similar minimum, 61 cm above the bottom of the washer. So if the hose is lying on the floor or stuck into a floor drain, that’s the first thing to fix. Check your own washer’s manual, because the figure differs between brands.

   You can check it
2. Don’t push it deep into the pipe or tape it

   If the hose goes a long way down the standpipe, it can siphon even when the pipe is high enough. Whirlpool says the hose should go no more than about 113 mm into the drainpipe; the figure differs between makers, so follow the one in your washer’s manual. LG and Whirlpool both say never to seal the hose into the pipe with tape or anything else: a small air gap around it has to stay open, because that gap is what breaks the siphon.

   You can check it
3. The hose is hung in place and not sitting in water

   On top-load washers, Samsung asks for the hose to be hung on the hook or holder at the back of the machine, with its end never submerged in water (a bucket or a full floor drain). It also says not to extend the hose beyond 3 metres, or run it over a doorsill more than 5 cm above the floor.

   You can check it
4. Twin-tub (semi-automatic): the wash/drain selector

   A twin-tub washer has a wash/drain selector. Midea’s manual, for example, says to choose “Normal” or “Heavy” for washing and rinsing, and “Drain” for draining. If the selector is on Drain, or stuck between positions, water runs out as you fill. If your model drains upwards with a pump, Midea’s manual puts the hose at least 86 cm high and no higher than 100 cm.

   You can check it
5. The plug test: does water come in with the washer off?

   While the washer is filling, pull the plug out of the socket with dry hands. If the water stops coming in, the inlet valve is closing properly. If water keeps coming in with the washer unplugged, the valve is stuck open and needs a technician. Turn off the water tap until then.

   You first, then a technician

6 signs that tell you where the problem is

Run a normal cycle, stay next to the washer for the first minutes of filling, and watch where the water goes:

1. Water comes out of the hose end as soon as filling starts, and the hose is on the floor or in a floor drain

   Likely cause: Siphoning: the hose is lower than the water level in the tub. Raise it to the height in the manual and it stops

   You can check it

2. The hose goes a long way into the pipe, or is taped to it

   Likely cause: There’s no air gap to break the siphon. Pull it up a little, leave space around it, and secure it without sealing

   You can check it

3. The washer fills, drains and repeats, then stops with an error or won’t finish the cycle

   Likely cause: The washer senses too little water because it keeps running out. On Samsung this can show as 4C or LC. Start with the hose; if it’s set right, the sensor needs checking

   You first, then a technician

4. The hose is at the right height with an air gap, and water still drains straight away

   Likely cause: Samsung points to the drain pump or the water level sensor here: if the sensor reads wrong, the washer drains too early

   Needs a technician

5. Water keeps coming into the tub even after you pull the plug

   Likely cause: The water inlet valve is stuck open. Turn off the tap; the repair is a technician’s job

   Needs a technician

6. A twin-tub that drains downwards leaks water from its hose while the selector is on Wash

   Likely cause: The selector isn’t closing off the drain: it’s stuck, or there’s dirt or a fault in the drain inside. Move the selector firmly to Wash and check; if it continues, it needs checking

   You first, then a technician

A quick test: While the water is running out, lift the hose end by hand above the water level inside the washer. If the flow stops and the pump isn’t running, the cause is most likely siphoning from the hose, not a fault in the washer, and refitting the hose at the right height is all it needs.

How to fit the drain hose correctly, step by step

• Unplug the washer, and turn off the water tap if you’re going to move it.
• Check your washer’s manual: what height the hose end needs, and whether it drains with a pump or by gravity (some top-load and twin-tub models drain downwards).
• If it drains with a pump: raise the hose in a U shape on the holder that comes with the washer, with its end at the height in the manual (Samsung: 60 to 90 cm above the floor).
• Put the end only a short way into the pipe, leave it loose with no tape, and tie the hose itself so it can’t fall out.
• Make sure the hose isn’t kinked or squashed behind the washer, then run a short cycle and watch the start of the fill.

If the water stops running out after you raise the hose, the problem was siphoning and it’s fixed without any part. But if the hose is set right and water still drains straight away, or water comes in with the washer unplugged, the cause is inside the washer: the water level sensor, the inlet valve or the drain pump, and those need a technician.

What a technician checks