If a Washing machine fills with water and drains it away at the same time there are a few possible causes. This unexpected behaviour can get the washing machine stuck in a vicious cycle. The water could be siphoning down the drain due to an issue with the plumbing. Or it could be aborting the wash program because it’s detected a fault. Careful observation of where on the cycle the issue occurs will help to work out which of these different faults is causing the problem.
Is Water Draining Out or Being Pumped Away?
The first thing to establish is how the water is leaving the washing machine as it tries to fill up. If the drain pump is definitely not running, but water is being lost down the drain then it must be siphoning. See my in depth explanation of siphoning later in this article.
Water is being pumped away
If you can hear the drain pump running, and the water is being pumped out just as it does at the beginning of the spin cycle, then it could be aborting the wash. Don’t confuse the water pump with a recycling pump (if fitted). They just recirculate water back into the drum.
Could be Overheating
Modern washing machines detect and react to the water being overheated. They can start pumping the hot water away. They may simultaneously take in cold water to cool everything down. If this is what’s happening it should also indicate an error code by flashing lights or lighting up specific option lights or displaying an specific error code via a digital display.
If overheating is the cause of this fault it should happen on the wash cycle. It should also happen after at least half an hour or so when the water has heated up. You should also be able to see that the water inside is very hot. I would also expect this behaviour to be relatively short lived. If the washing machine thinks it has overheated and has aborted the wash cycle, then all it needs to do is cool things down and pump away all of the water. Once this is done it should turn off displaying an error code.
This fault could also be caused by a faulty thermistor (thermostat) giving false readings. If you think you have this fault you’d be better finding an engineer but I have a general help article here – How to test an NTC thermistor.
Other Faults
If the pump runs continuously as soon as the washing machine is turned on and won’t shut off there could be insulation faults on the machine. Call an engineer.
Siphoning Water
If water is just draining away all the time but not being actively pumped out, this is siphoning. The washing machine is trying to fill the drum with water, but water is being lost down the drain. It will keep detecting there isn’t enough water inside and top up with more. Modern washing machines should be sophisticated enough to realise something’s wrong and abort with an error. If not, it may get stuck in this cycle indefinitely.
Siphoning occurs when the end of the drain hose is lower than the level of the water inside the washing machine. My diagram shows a correctly plumbed in washing machine. The end of the drain hose is higher than the level of water in the drum.
Water always levels. So you can see the water in the drain hose matches that of water in the the drum. If the drain hose was pushed down the waste water pipe much further, or the pipe it pushes into falls over, then water can start to siphon out.
Siphoning can start by the force of gravity, or when water is first pumped out of the machine. The latter happens in the same way as you’d siphon petrol from a car, by sucking the pipe to start the liquid flowing. Remember: if the pump is running it is not siphoning. Also, siphoning is not likely if the drain hose is connected to the u-bend under the sink because it’s so high up.
Has the Washing Machine Been Moved recently?
Siphoning most often occurs when the washing machine has been moved out for cleaning or relocated in a new house etc. It can also occur if a stand pipe isn’t properly secured to the wall and falls over at an angle.
When pushed into a stand pipe the drain hose should have a drain hose crook at the end. This not only helps keep the drain hose from falling out but stops it being pushed too far down. The length of drain hose sticking out of the crook should roughly be about 4 or 5 inches.
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Full instructions for the exact height of the stand pipe should be available in the instruction manual, or on separate installation instructions that came with the machine.
Overfilling?
If the washing machine overfills it should not simultaneously fill with water. However, if the end of the drain hose is in a standpipe, and low enough, it could trigger siphoning. Water can start to flow out of the drain hose and down the drain caused by the higher level of water in the drum. The washing machine detects the loss of water and keeps filling. This would be rare though. If the siphoning wasn’t triggered, the washer would overfill and flood. If you can see the water levels in the drum are way too high and your washing machine is definitely overfilling try here overfilling.
Don’t get carried away
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Hi Andy, Thanks for your help & advice. We have decided on buying a New machine as repair costs to our old one are more than its worth.
I did wonder if reflowing the board with heat gun may cure it? Would it be worth a shout? I don’t like things like this to beat me…!
Again many Thanks.
The only thing I would suggest Paul, would be to send the PC board to get tested and potentially repaired to somewhere like QER Repairs (eBay) who specialise in repairing PCBs for washing machines and other appliances. They would either repair it or test it and return saying there’s nothing wrong with it.
Dear MR Andy,
Just got my Samsung Washing machine top loader few days ago. As soon as i start a wash, the water immediately start rushing out of the Hose mouth thereby hindering the water from getting to the desired level to begin a wash. Are u saying that i should lift up the Hose above the water level of the washing machine or what?
Kindly respond sir as am thinkn of returning the product.
Hello Adekoya. The instruction book should tell you exactly how the drain hose should be installed but if the end of the drain hose is lower than the top of the water in the drum it will just siphon out through gravity. If you take a washing machines’ drain hose whilst it is full of water and slowly lower it into a bowl or bucket, when it gets to a certain level the water will just flow out without being pumped.
Try holding the drain hose high above the washing machine and let the washing machine start to fill up with water. Hold the end of the drain hose in a bucket just in case by any chance the washing machine starts to pump water otherwise you will have water everywhere.
If the washing machine fills up and washes as normal this would indicate that your problem is related to the drain hose being too low. It should be pushed into a drain pipe but not so far down as to cause siphoning as described in my article above headed “Siphoning water”.
If by any chance the washing machine is actually pumping this water out instead of it siphoning then this is a different problem.
The drain hose should not be too high either. This could limit its pumping efficiency.
Dear MR Andy,
I just narrated the solution to my Wife now. She raised the hose a bit and the Water no longer drains unnecessarily.
Really appreciate this forum. It has saved me time, energy, money e.t.c.
One last thing please, my Washing machine has a SOAK PROGRAM. is it right to pour a little bit of bleach into the washing machine when making use of the soak program for my white Shirts and underwear?
1st class solution work straight after reading diagnosis
i had recited washing machine in utility room and hadn’t raised the outlet pipe
cheers
Hey Guys,
Thanks a lot I managed to sort out my machine.
It was siphoning as my wife asked me to a make a troy so that can wheel in and out of the bathroom, but I made the mistake of putting the drain pump in the bathtub which lower than the drum.After I read the the section of siphoning I changed the drain pipe to the sink which was higher than the drum and boom, no more water coming out as it washes.
Hello, i have a washing machine that is definitaly siphoning after being ran thru spin. If only for a moment. Even if there is only a few inches of water in the tub. The standpipe is 31″ tall. Does rise higher than the hight of water level in the machine and Does have a p-trap and a open vent. My only difference is that i had to seal the hose to the stand pipe. Due to water backing up. Has worked for a long time this way but now has began to siphon. It seems the only way to get the siphon to stop is to break the seal at the hose & standpipe connection. Any ideas or clues as to why this would start now? The drain has had maintenance and is believed to be too small for the discharge output of the washer. But had worked for years. Any thoughts?
Hello Ben. It sounds like your problem is water siphoning back into the machine rather than water siphoning out of the machine on wash or rinse?
If you had to seal the drain hose into the standpipe because water backed up and leaked out of it this means there is a partial blockage in the standpipe which needs clearing. The blockages usually occur inside any bends, usually the 90° ones. This very same fault is what is highly likely to be causing water to siphon back into the machine because water is not being pumped away fast enough. Water is therefore backing up in the standpipe right up to the end of the drain hose. With the drain hose sealed in the water is going down the drain hose back into the machine instead of pouring out onto the floor.
A drain hose going into a standpipe should not be sealed in, there should be airflow around the drain hose. Once you locate and remove the partial blockage in the standpipe you should be able to refit the drain hose properly.
When I drain the water out my sink it’s goes into the washing machine. What can I do