Washing Machine Fills With Water When Off
If your washing machine has water in the drum when you have not run a cycle, or is slowly filling up overnight, there are only two possible entry points for that water: a faulty water inlet valve, or a drain hose that is not installed correctly. This guide explains how to identify which is the cause, how to diagnose the fault in each case, and what the fix involves.
Water in the drum when the machine is switched off comes from either a faulty or debris-blocked water inlet valve, or from siphoning through an incorrectly installed drain hose. Clean water points to the valve. Dirty or smelly water points to the drain hose. Check which type of water is present to direct the diagnosis immediately.
Step One: Identify the Water Type
The first diagnostic step is simple and takes no tools at all. Look at the water in the drum and assess it carefully.
Points strongly to a faulty water inlet valve. The valve is allowing mains water to seep past when it should be closed. The water is clean because it is coming directly from the mains supply. Go to the inlet valve section below.
Points strongly to drain hose siphoning. Water from the household drain system is being drawn back into the machine through an incorrectly installed drain hose. This is actually the most common cause of the two. Go to the drain hose section below.
If the water appears clear but has a musty or stale smell, it may have been sitting in the drum for some time after entering via a slowly seeping valve. This is still most likely a valve fault. The smell develops from the stagnant water rather than from a drain source.
Cause 1: Faulty Water Inlet Valve
The water inlet valve controls the flow of mains water into the washing machine. When the machine is not running, the valve should be fully closed, preventing any water from entering regardless of whether the tap is turned on. When a valve develops a fault, it can allow water to seep past slowly, filling the drum over hours or overnight.
Why valves fail
The valve contains a rubber diaphragm or solenoid mechanism that physically closes the water path when the machine is not filling. If this mechanism develops a fault, wears, or stiffens with age, it may not close completely and water seeps through slowly.
Small particles of grit, limescale, or debris from the water supply can lodge in the valve seat and prevent it from closing fully. This is more common on older machines, in areas with hard water, or following any work on the mains supply that disturbs the pipework.
Washing machine inlet valves use water pressure to help maintain the closed position. A blocked filter screen at the valve inlet reduces that pressure, which can prevent the valve from seating fully. A severely blocked filter is a less common cause but worth checking before condemning the valve.
Some inlet valves rely on a minimum incoming pressure to push a rubber flange into the closed position. If the water pressure is very low, this seal may not engage fully and water can seep past. Read more: low water pressure and washing machines.
How to confirm the valve is the source
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Turn off the water tap(s) to the washing machine. These are the isolating taps behind or under the machine on the inlet hoses. Turn them off fully and leave the machine switched off for several hours or overnight. If no water appears in the drum, the fault is confirmed as valve-related, and the tap was the supply source.
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Verify the tap itself is not faulty. A tap can appear closed externally but be failing internally. To confirm the tap is actually shutting off the water, disconnect the fill hose from the back of the machine and point it into a bucket. Turn the tap off and check no water flows through. If water still comes through with the tap turned off, the tap itself needs replacing.
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Observe the soap dispenser for slow dripping. Remove the dispenser drawer and look into the dispenser housing with the machine switched off. If water is slowly dripping in at intervals through the nozzles at the top of the housing, the valve is seeping. Do not check this immediately after a wash cycle as some residual dripping for a short period after filling is normal. If you also see a black jelly-like build-up around the entry points, read our guide on black jelly in the soap drawer.
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Check the inlet valve filter. Turn off the tap and disconnect the fill hose from the back of the machine. The inlet valve filter is a small mesh screen visible at the back of the valve inlet. It should be clean. If it is visibly blocked with scale or debris, carefully pull it out with flat-nosed pliers and rinse it under a running tap. Handle it gently as even a small hole in the mesh compromises its function. Refit, reconnect the hose, turn the water back on, and recheck.
What to do if the valve needs replacing
If the filter is clean, the water pressure is adequate, and turning off the tap stops the water entering, the inlet valve itself needs replacing. Water inlet valves are a common spare part for most mainstream washing machine brands and are available through independent spare parts suppliers. You will need your exact model number to order the correct valve. See our spare parts guide for sourcing.
Valve replacement involves disconnecting the machine from the mains, disconnecting the fill hose, and accessing the valve from the back panel. On most machines it is a straightforward repair. If you are not confident working on electrical appliances, a qualified engineer should carry out the replacement.
Cause 2: Drain Hose Siphoning (Most Common)
Drain hose siphoning is actually the more common of the two causes, and it is almost always the result of the drain hose not being installed correctly. When the drain hose does not rise high enough before connecting to the household drain, water from the sink or drain system can run back down the hose and into the machine by gravity or siphon action.
The water entering via this route is dirty because it comes from the household drain, explaining the murky or smelly appearance in the drum.
How the drain hose should be installed
The correct installation requires the drain hose to rise to a height of at least 60cm to 80cm above floor level before connecting to the household drain or standpipe. This rise creates an air break that prevents back-siphoning. Most washing machines are supplied with a formed plastic hook or clip that holds the hose at the correct height on the back of the machine before it drops down to the drain connection.
Drain hose connected to the U-bend under the sink
This is the most common drain connection arrangement in UK kitchens. The washing machine drain hose connects to a dedicated inlet on the U-bend pipe under the sink. For this to work safely, the hose must rise up before connecting down into the U-bend.
If the hose runs in a straight horizontal or downward path from the machine directly into the U-bend, any water poured down the sink can follow the hose directly into the washing machine. Even a hose that rises slightly but then dips back down before the connection can allow siphoning. The hose must rise to the correct height and stay there, using a cable tie to the back of the machine or the wall if necessary.
Drain hose connected to a standpipe
If the drain hose runs into a dedicated standpipe rather than a U-bend, siphoning is less likely but still possible in certain circumstances. The drain hose must sit inside the standpipe with an air gap around it, not be sealed into it with tape or putty. A sealed connection removes the air break and can create a siphon. Additionally, if the standpipe outside is submerged in water due to a blocked drain grate, water can be forced or siphoned back up the pipe. Check that the hose sits freely inside the standpipe and that the external drain is clear. Read: how to check the drain hose is installed properly.
How to fix a siphoning drain hose
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Pull the machine out slightly and trace the drain hose. Follow the hose from the back of the machine to where it connects to the drain. Note whether the hose rises to a height of at least 60cm before coming back down to the connection point. If it runs downward without rising, the installation is incorrect.
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Reposition the hose to create a proper rise. The hose needs to loop up as high as possible before descending to the drain connection. Use the plastic hose clip provided with the machine to hold it at the correct height on the back panel, or use a cable tie to fix it to the wall at the correct height.
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Ensure there is an air gap at the drain connection. If the hose connects to a standpipe, it must sit loosely inside the standpipe with space around it, not be taped or sealed into it. If the hose connects to a U-bend fitting, the fitting should have a proper air break built in.
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Run a test cycle and check for siphoning. After correcting the installation, run a cycle and observe whether the machine drains fully. Then leave it unused for several hours to confirm water is no longer entering the drum.
Safety: Turn Off the Taps When Not in Use
Regardless of which cause applies to your machine, this fault is a strong reason to adopt the habit of turning off the water supply taps to the washing machine after every use. A machine that is filling with water overnight can overflow if unnoticed, and a slow leak from a faulty valve can become a fast leak without warning.
The taps should take seconds to turn and the benefit, particularly when going away on holiday or leaving the house for extended periods, significantly outweighs the small inconvenience. Read our full guide: should you turn off the washing machine taps after each use?
If the water inlet valve needs replacing, or you would prefer a professional to diagnose and fix the fault, NAC Repair provides same-day and next-day nationwide appliance repairs. For parts, our spare parts guide links to trusted UK suppliers.
Frequently Asked Questions
Why does my washing machine fill with water when it is switched off?
There are only two ways water can enter a washing machine when it is not running: through a faulty or debris-blocked water inlet valve, or by siphoning back through the drain hose. Clean water in the drum points to the valve. Dirty or smelly water points to the drain hose. Both causes and their fixes are described in full in the guide above.
How do I know if it is the valve or the drain hose causing the problem?
Check the water in the drum. If it is clean and clear, the inlet valve is the likely cause. If it is dirty, murky, or has a drain smell, the drain hose is the likely cause. You can also turn off the water supply taps to the machine. If water stops entering overnight with the taps off, the valve is confirmed as the source. If water still enters with the taps off, the drain hose is the cause.
I turned off the mains water supply and still found water in the drum. How is this possible?
If the mains supply is genuinely off and no water is reaching the inlet valves, the only remaining source is the drain hose. Water from the household drain system, including any water that runs down the sink, can siphon back into the machine through a drain hose that is not installed at the correct height. Check that the drain hose rises to at least 60cm before connecting to the drain, and that there is an air gap at the connection point rather than a sealed fitting.
The water in my drum is clean but the machine still fills overnight. Could it be the drain hose?
It is possible but less likely. Drain hose siphoning typically introduces dirty water because it draws from the household drain. If the water is consistently clean, the inlet valve is the more probable cause. However, if the drain hose connects to a clean water source in an unusual installation, or if the water has been sitting long enough to appear clear, the drain hose cannot be entirely ruled out. Turn off the inlet taps and check whether water still enters with the taps off to confirm.
Why does low water pressure cause a washing machine to fill when off?
Some water inlet valves use the pressure of the incoming water supply to push a rubber seal into the closed position. If the incoming pressure is very low, this seal may not engage fully and water can seep past slowly. This is a less common cause than valve wear or debris, but it explains why some households experience this fault even on relatively new machines. Read our guide on low water pressure and washing machines.
My new washing machine is filling with water when off. Can a brand new valve be faulty?
A manufacturing defect in a new valve is possible but uncommon. On a brand new machine, the drain hose installation is more likely to be the cause, particularly if the machine has just been connected up and the drain hose has not been checked for correct routing and height. Check the drain hose installation first before suspecting a faulty new valve. If the drain hose is correctly installed and the machine is still filling via the valve, contact the retailer as a manufacturing fault on a new appliance is covered by your consumer rights.
Is it safe to use the machine while it is filling with water when off?
Technically the machine may wash normally if the underlying fault is only causing slow seepage. However, a valve that is seeping slowly can fail further without warning and allow much faster flooding. The risk of overflow and water damage is real. Turn off the supply taps when the machine is not in use and arrange a repair as soon as possible. Do not leave the machine unattended with the taps on until the fault has been resolved.
Hello, when I’m using the short programs on my Hotpoint NSWF944 1400 Spin 9Kg Washing Machine like 30 min and 45 min shortly in that day it starts to fill up will water, but not on other programs which they are significant longer. Any of you notice the same problem or is just me?
Hello there. Do you mean that when the washing machine has finished it starts to fill up with water over the next few hours? It seems a little unusual that it would seem to do it only after certain wash cycles, but there are only 2 possible causes for water going into the machine and they are described in detail in the article.
I would suspect in your case it’s more likely to be water siphoning back into the washing machine through the drain hose because the drain hose isn’t installed properly. Check out the article and the photos that describe this problem in detail. This is of course assuming that your washing machines drain hose is connected to the U bend under the sink.
Just bought new washer dryer as water was filling old machine overnight and flooding. Came down this morning and still same problem so wasn’t machine. It stops if I switch blue tap under sink. Please can you help?
Hello valve. All of the possible causes that I am aware of are described in my article. If it has done it on two separate washing machines, and it definitely stops when you turn off the water valve, then read the section about low water pressure.
We have been away for 3 weeks and turned the water off at the mains before we went. In our return the drum in my washing machine had filled with water and was all over the floor as I had left washing machine door open how can this happen
Hello Margaret. Must be very annoying. Especially with the door being left open although, by the sounds of it, if you had closed the door then the water would have risen above the level of the door and poured out all over your feet when it was opened.
My article above lists all of the possible causes for water to enter the washing machine. It can only come in from the drain hose or from the water valve. As the sink was not in use at the time it only really leaves the water valve. So the only way water could have got in his if the water wasn’t turned off fully, either due to needing a little bit of an extra turn or the mains tap not shutting off properly inside. Another alternative is if by any chance the water supply to the washing machine is supplied through a tankful of water. If by any chance it is a hot and cold fill washing machine, maybe the water valve that let in the water was from the hot water tap on the washing machine, which may be fed through a hot water cylinder?
I would turn off the mains again, just like you did before you went on holiday, and then try putting the washing machine onto a wash cycle to see if any water comes into the washing machine. No need for any laundry detergent, but this will test to see if water is still going to the water valves with the mains stop tap turned off. If no water goes in, you could try just turning the stop tap just 1/4 of a turn to see if any water comes in, which might explain water get into the washing machine if it wasn’t fully turned off.
My front load Electrolux washer filled the tub when the unit was off. I checked the taps they do it leak when hoses are disconnected. What else could be causing the tub to fill when the washer is off?
Hello Lisa. I only know of 3 possibilities, and they are all described in the article.
Hi Sheila, I can’t advise anything that isn’t already explained in my article. Everything that could possibly cause it and what to try is in the article.
My washing machine when not in use has water in the drum which looks clean but is smelly my washing is clean and smells ok what can be the problem.
Hello Shailesh. If the water is clear, and entering the drum overnight or when the washing machine is not on, it is usually coming from a leaking water valve as described in the article. The only other possible place for water to get into a washing machine is through the drain hose.
Water coming from washer drain pipe but no water running in any bathroom or sink. Water was clear. This happened before but water was dirty that time. Any thoughts?
Very strange Connie. It sounds like the water valve is stuck open.