Washing machine fills and drains at same time
A washing machine that fills and drains simultaneously is usually caused by one of two things: the drain hose is siphoning water away due to incorrect plumbing, or the machine is deliberately pumping water out because it has detected a fault such as overheating. The first step is to determine whether the water is draining by gravity or being actively pumped out – this immediately separates the two fault types.
Observing exactly where on the cycle the problem occurs, and whether the drain pump is running, narrows the cause significantly and determines what to look at next.
Step 1: Is the Water Being Pumped Out or Draining by Gravity?
This is the most important diagnostic question. Listen carefully while the machine is trying to fill.
Drain pump is NOT runningWater is draining by gravity – this is siphoning. The drain hose is too low and water is flowing out without the pump running. See the siphoning section below.
Drain pump IS runningThe machine is actively pumping water out – this is a controlled response to a detected fault, most commonly overheating. See the fault pumping section below.
Do not confuse the drain pump with a recirculation pump if fitted. Recirculation pumps run during the wash cycle and return water back into the drum – they do not pump water away. The drain pump is the one that empties the machine during rinse and spin cycles.
If the Pump Is Running: Possible Fault Causes
Overheating
Modern washing machines monitor water temperature and will abort the wash cycle if the water overheats. The machine pumps out the hot water and may simultaneously draw in cold water to reduce the temperature. When this happens, the machine should also display an error code – either through flashing indicator lights or a code on the digital display.
Overheating will typically occur on the wash cycle, and only after at least 30 minutes have elapsed – enough time for the water to have reached temperature. The water inside the drum should be visibly very hot. Once the machine has pumped away the water and cooled down, it should switch off and display the error code.
A faulty thermistor (temperature sensor) can also trigger this behaviour by sending false high-temperature readings to the control board, causing it to abort unnecessarily even when the water is not actually overheating. See our guide on how to test an NTC thermistor – though this type of fault is generally best investigated by a qualified engineer.
Continuous Pumping From Switch-On
If the drain pump runs continuously from the moment the machine is switched on and will not stop, this may indicate an insulation fault within the machine. Do not attempt to investigate this further – switch the machine off and contact a qualified engineer.
If the Pump Is NOT Running: Siphoning
Siphoning occurs when the end of the drain hose is positioned lower than the water level inside the washing machine drum. Water always seeks its own level – if the drain hose end is below the water in the drum, water will flow out continuously by gravity without any pump being needed, in the same way liquid siphons through a tube.
The washing machine detects that the water level is falling, and responds by filling with more water – creating a cycle where it fills and drains simultaneously. Most modern machines will eventually detect this as a fault and abort, displaying an error code. If the machine does not detect it, the cycle can continue indefinitely.
The drain pump is running – pumping and siphoning are mutually exclusive. Siphoning is also very unlikely if the drain hose connects to the U-bend under the sink, as this connection point is high enough to prevent it.
What Causes Siphoning?
Siphoning most commonly occurs when the washing machine has been moved – pulled out for cleaning, or relocated to a new property – and the drain hose has been pushed too far down into the standpipe, or the standpipe has tilted or fallen over. The drain hose end must remain above the water level inside the drum at all times.
How to Fix Siphoning
The drain hose must not be pushed too far down into the standpipe. The correct installation uses a drain hose crook – a curved fitting at the end of the drain hose that hooks over the top of the standpipe. This prevents the hose from being pushed too deep and also helps keep it in place. The length of hose extending below the crook into the pipe should be no more than approximately 10 to 15cm.
The standpipe itself must be adequately secured to the wall so it cannot tilt or fall. Full installation height requirements for the standpipe should be in the machine’s instruction manual or on the installation sheet supplied with it. See our full guide on how to install the drain hose correctly, and our guide on connecting a washing machine properly.
Could It Be Overfilling Instead?
If the water level in the drum is visibly much higher than normal, the fault may be overfilling rather than siphoning or a fault abort. In some cases, an overfilling machine can trigger siphoning – the higher water level causes water to flow out via a correctly-positioned standpipe through gravity. If you can see the drum is clearly overfilling, see our guide on washing machine overfilling.
Need a Qualified Engineer?
If the fault persists after checking the drain hose position, or if the pump is running continuously, a qualified engineer should investigate.
Related Guides
How to Install the Drain Hose CorrectlyCorrect drain hose installation including standpipe height, anti-syphon requirements, and common mistakes that cause drain faults.
Washing Machine OverfillingIf the drum water level is much higher than normal, the issue may be overfilling rather than siphoning.
How to Connect a Washing Machine ProperlyA complete guide to connecting inlet and drain hoses correctly, including standpipe height requirements.
DIY Repair Safety GuideEssential safety rules before working on any washing machine – electrical or otherwise.
Frequently Asked Questions
Why is my washing machine filling and draining at the same time?
There are two main causes. If the drain pump is not running, the water is siphoning out due to the drain hose being positioned too low – a plumbing issue that can usually be fixed by adjusting the drain hose position. If the drain pump is running, the machine is deliberately pumping water out because it has detected a fault, most commonly overheating or a sensor error.
How do I know if my washing machine is siphoning?
If the drain pump is not running but water is still leaving the drum, the hose is siphoning. This typically happens when the machine has recently been moved and the drain hose has been pushed too far into the standpipe, or the standpipe has tilted. Siphoning is not possible if the pump is running, and is very unlikely if the drain hose connects to the U-bend under the sink.
How do I stop my washing machine drain hose from siphoning?
Ensure the end of the drain hose is correctly positioned using a drain hose crook – a curved fitting that hooks over the standpipe and prevents the hose being pushed too deep. The hose end should extend no more than approximately 10 to 15cm into the standpipe. The standpipe must also be properly secured to prevent tilting. Correct standpipe height requirements are detailed in the machine’s installation instructions.
Could overheating cause a washing machine to pump out water while filling?
Yes. If the machine detects the water has overheated, it will pump out the hot water and may simultaneously bring in cold water. This should only happen on the wash cycle after at least 30 minutes of running, the water should be visibly very hot, and the machine should display an error code. A faulty thermistor can trigger the same response with false readings even when the water is not actually overheating.
What should I do if the drain pump runs continuously from switch-on?
Switch the machine off immediately and contact a qualified engineer. Continuous pump operation from the moment the machine is switched on, without any fill cycle occurring, may indicate an insulation fault. This is not a fault to investigate or work around without professional assessment.
30 Comments
Grouped into 17 comment threads.
3 replies Thank you for the article it was very insightful, but I still don't think that my problem is listed here. So I have a 3-year old Samsung washer, and when I press the power button, the drain pump turns on, without even pressing start. It continues to pump constantly, regardless of whether the washing machine is in a cycle or not. So as soon as I start a cycle, the water is drained and never has a chance to fill up. I don't believe that the computer is recognizing this as an overheating problem, because there aren't any lights flashing. After working for a little, there is an NF or No Fill error. I know that's a mouthful, but I'm wondering if you can help me out.
0 replies Thank you!!!!! I had shoved the drain hose down a bit last week---then was having the fill/drain situation in the rinse cycle. Just changed the hose a bit and I'm up and running! You saved me so much trouble with this advice. Awesome!!!!!!!!!!
Thank you!!!!! I had shoved the drain hose down a bit last week—then was having the fill/drain situation in the rinse cycle. Just changed the hose a bit and I’m up and running! You saved me so much trouble with this advice. Awesome!!!!!!!!!!
0 replies thanks, my washer was siphoning bc the drain hose was so long the end inside the stand pipe was lower than the water level. Problem solved!
thanks, my washer was siphoning bc the drain hose was so long the end inside the stand pipe was lower than the water level. Problem solved!
1 reply hi I have new hotpoint washing machine when I start a wash program the washer fills a bit with water then pumps out waits a few seconds then fills again then the wash cycle washes is this normal I have no flashing lights on machine to say theres any problem hope you can help thanks
hi I have new hotpoint washing machine when I start a wash program the washer fills a bit with water then pumps out waits a few seconds then fills again then the wash cycle washes is this normal I have no flashing lights on machine to say theres any problem hope you can help thanks
Likely replying to diane
Hello Diane. Modern washing machines usually fill up with water for a few seconds then stop before taking in the detergent. This is to prevent detergent being washed into the sump hose and wasted. If it fills up and pumps the water out for several seconds it’s probably just trying to flush away old water left in the sump hose after the previous wash. If it washes and spins as you would expect it’s very unlikely there is a fault.
0 replies You need this article beb washing machine fills with water when off (or when water poured down sink).
You need this article beb washing machine fills with water when off (or when water poured down sink).
0 replies When I drain the water out my sink it's goes into the washing machine. What can I do
When I drain the water out my sink it’s goes into the washing machine. What can I do
1 reply 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, 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?
Likely replying to Ben
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.
0 replies 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.
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.
0 replies 1st class solution work straight after reading diagnosis i had recited washing machine in utility room and hadn't raised the outlet pipe cheers
1st class solution work straight after reading diagnosis
i had recited washing machine in utility room and hadn’t raised the outlet pipe
cheers
0 replies 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?
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?
1 reply 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.
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.
Likely replying to Adekoya Adekunle
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.
0 replies 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.
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.
4 replies Hiya, my Samsung w/m is filling and draining at the same time! My problem first started by the opposite. It would not drain. I could smell a burning smell. So I checked for blockages and changed the pump for new. Now when I switch on the w/m, start a wash cycle, it starts filling but is emptying at the same? The pump is activating whilst filling. I know this as when I disconnect the pump it fills up? Wot could this new problem be now please? Any advice would be much appreciated . Cheers, Paul
Hiya, my Samsung w/m is filling and draining at the same time! My problem first started by the opposite. It would not drain. I could smell a burning smell. So I checked for blockages and changed the pump for new.
Now when I switch on the w/m, start a wash cycle, it starts filling but is emptying at the same? The pump is activating whilst filling. I know this as when I disconnect the pump it fills up? Wot could this new problem be now please? Any advice would be much appreciated . Cheers, Paul
Hiya, Thanks for replying! Yes if I disconnect the pump it starts to fill as per normal. Its definitely not siphoning problem as machine as always been where it is without a problem for the last 5 years. I also replaced the pressure switch for new but that has made no difference either? Cheers, Paul
Likely replying to Paul Norris
Hi Paul. The only pressure switch possibility would be if it was jammed on the highest switch level (flood protection) which passes power directly to the pump. I was wanting to know if the water stopped filling at the correct levels and started to wash (and didn’t overfill). This would have shown the pressure system to be working ok.
Without a wiring diagram I don’t know if the pump is switched on by switching in a neutral return or if it has a constant neutral return and the pump is switched on the old fashioned way by just sending power to it.
If the old pump burned-out maybe it’s damaged something in the PCB jamming the switching on.
Likely replying to Andy Trigg (Whitegoodshelp)
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.
1 reply Thank you so much this article saved me so much in tears and tantrums. I successfully fixed our siphoning problem when we moved the machine into our new property. Your article was easy to understand and highly recommend it. Great work
Thank you so much this article saved me so much in tears and tantrums. I successfully fixed our siphoning problem when we moved the machine into our new property. Your article was easy to understand and highly recommend it. Great work
Likely replying to Soraya
Thanks Soraya.
Beverly, If it pumps out the water about 10 mins in then it sounds like it’s aborting the programme due to detecting an error. If so it might be displaying an error code – Appliance Error codes and What You Need to Know Once suspect could be not heating due to a heater fault.
0 replies hello. I have a problem similar. but not quite like these. my washer will get both cold and hot water. it will begin to fill but will drain 10 minutes later without going to spin cycle. now spin cycle works when I manually move it to spin and rinse and spin again. but the washer never completely fills so that it can move to spin. I have to force it and the water always comes out the drainage hose. what is the problem?
hello. I have a problem similar. but not quite like these. my washer will get both cold and hot water. it will begin to fill but will drain 10 minutes later without going to spin cycle. now spin cycle works when I manually move it to spin and rinse and spin again. but the washer never completely fills so that it can move to spin. I have to force it and the water always comes out the drainage hose. what is the problem?
1 reply My hotpoint aquarius wml540p was stopping after the wash, the drain pump wasn't coming on and all the lights were flashing. I've renewed the pump but now it is filling and draining water - the pump is coming on almost as soon as the machine is started. The drain set up hasn't changed from before the pump broke down. Grateful for any advice.
My hotpoint aquarius wml540p was stopping after the wash, the drain pump wasn’t coming on and all the lights were flashing. I’ve renewed the pump but now it is filling and draining water – the pump is coming on almost as soon as the machine is started. The drain set up hasn’t changed from before the pump broke down. Grateful for any advice.
Likely replying to Colette
Hi Colette, are you sure water isn’t siphoning down the drain due to the drain hose being disturbed as described in this article under “Siphoning water”? That’s the most likely explanation. If the pump is actually running and you can hear it pumping (as opposed to the water just draining away on its own) that would be unusual after just fitting a pump. Make sure the wires are correctly fitted to it including any earth lead.
1 reply This is the best info I have found related to my problem but it only happens on the rinse cycle. I will try adjusting the hose but could this siphoning effect happen only during the rinse cycle? My machine is filling and running through the wash cycle with no trouble. It drains and spins fine but when it hits rinse it is doing exactly as you discribe. The water is going in and out at the same time so the cycle never advances. I thought it was the switch at first but it happens on every setting (normal, perm. press, ect.).
This is the best info I have found related to my problem but it only happens on the rinse cycle. I will try adjusting the hose but could this siphoning effect happen only during the rinse cycle? My machine is filling and running through the wash cycle with no trouble. It drains and spins fine but when it hits rinse it is doing exactly as you discribe. The water is going in and out at the same time so the cycle never advances. I thought it was the switch at first but it happens on every setting (normal, perm. press, ect.).
Thank you for the article it was very insightful, but I still don’t think that my problem is listed here.
So I have a 3-year old Samsung washer, and when I press the power button, the drain pump turns on, without even pressing start. It continues to pump constantly, regardless of whether the washing machine is in a cycle or not. So as soon as I start a cycle, the water is drained and never has a chance to fill up. I don’t believe that the computer is recognizing this as an overheating problem, because there aren’t any lights flashing. After working for a little, there is an NF or No Fill error.
I know that’s a mouthful, but I’m wondering if you can help me out.
Likely replying to Yevgeny
Yevgeny, if the pump is running continuously as soon as the washing machine is switched on and won’t stop I’d suspect a possible insulation fault. Low insulation on some parts can cause weird faults but you’d need an engineer who has an insulation test meter to check it out.
Likely replying to Andy Trigg (Whitegoodshelp)
Hi Andy
Ive got a samsung top loader model no WA13UP.Ive been reading your article about siphoning(water running into loader and down the drain) Ive been using my toploader for years in the same position-the drain pipe and suddenly the water just started running down the drain as it pours in?The wash,rinse and spin lights are then on at the same time but the pump is not running-water just keep on pouring in and out through yhe drain pipe. Any suggestions on trouble shooting
Likely replying to Philip Venter
Hello Philip. If water is running down the drain as it fills up but the pump isn’t running it can only be siphoning out because the pipe is too low. I appreciate you don’t think anything has changed but there’s no other possible explanation. If the water is being pumped out by the pump though then that’s a fault and most likely caused by the machine detecting a fault and aborting the cycle.