This article looks at how a washing machine can fill with water when switched off. Sometimes overnight. When a washing machine is not in use, water may slowly seep inside, so that when you come to use it, you notice water in the bottom of the drum.
It could be clean water, or dirty water. It’s important to work out which type of water it is, because they have different sources.
There are only 2 places where water can get into a washing machine’s drum. Either seeping through a faulty water valve, or coming in through the drain hose. It’s impossible for water to get in any other way.
If the water is very clean, it might be coming in through a water valve. If it is dirty, it may be coming in through the drain hose. Both possibilities are described in detail below.
Water coming in through a water valve
If this is the problem, the water in the drum should be clean. When a water valve isn’t being used, it obviously shouldn’t let any water through – even if the water supply is still turned on.
It’s possible for a fault inside the valve to prevent it from shutting off properly. Or a small bit of grit or debris could get past the filter, and stop it from closing off properly.
The latter is unlikely though, unless it’s an old washing machine, or maybe there is some damage to the filter. Either of these issues can result in water slowly seeping into the machine.
Water rising inside the drum may only be noticed if the washing machine is left unused (with the water tap left on) overnight, or over a several day period. This is why, ideally, you should always turn off the taps after using the washing machine.
Water Pressure Too Low
A third possible valve related cause is if the water pressure is very low. Bizarrely, the valves rely on a minimum amount of water pressure to push against a rubber flange and shut water off. You can get water seeping past the seal inside if the water pressure is extremely low.
The first thing to try is to turn off the taps
If the water inside the drum is clean, then water could be getting past the water valve. Turn off the water tap(s) to the washing machine. Does this stop the water coming in?
If it doesn’t, move onto the drain hose possibility below. However, you must ensure the tap is not faulty by removing the fill hose from the machine and ensuring no water comes through with the tap turned off.
This is the only way to be 100% sure water is being properly turned off. This is because a tap can be faulty inside and not turn off properly.
Is water dripping in through the soap dispenser?
Sometimes, by removing the soap dispenser drawer and carefully observing inside the soap dispenser, you can see water slowly dripping in at regular intervals from the nozzles at the top. Don’t check this if the washing machine has just been filling though. You may get some dripping of water into the soap dispenser for a while after.
If there is a slow drip, you might also (but not necessarily) see a black jelly-like gunge around where the water comes in
Check the Water Valve Filter
Water pressure to the valve might be reduced enough to prevent the valve shutting off properly if the filter is severely blocked. Turn off the tap(s), remove the fill hose(s) and the water valve filter is easily seen at the back of the valve.
Usually it will be quite clean – with no need to remove it. If it is definitely blocked though, carefully pull it out with some flat pliers. Clean it out under a running tap.
Be very careful not to damage it! Even a very small hole will compromise its filtering abilities and let debris inside the valve.
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Does the water valve need replacing?
If the filter in the valve is not damaged, the water pressure is OK, and turning off the tap stops water entering the drum overnight, you need to get the water valve replaced as soon as possible.
Is water getting in through the drain hose?
The only other place water could possibly get into the drum is by siphoning up the drain hose. This is actually the most common cause of water getting into a washing machine. It shouldn’t be possible if the drain hose is plumbed in properly.
However, incorrect fitting can create circumstances where water runs down the drain hose, or is siphoned up through it.
If the drain hose is connected to the U-bend under the sink
If the drain hose is connected directly to the U-bend under the sink, and it does not rise up before running down to the washing machine, then water running down the sink can get into the washing machine.
The following photo shows drain hoses from a washing machine and a dishwasher. Both are poorly fitted. See how there is a direct run for water poured down the sink to continue down the drain hose into the appliance.
The following picture shows another two appliances plumbed into a U-bend under a sink.
The bottom one is another direct run for water poured into the sink to run down the drain hose into the washing machine.
The drain hose on the top is correctly fitted. A drain hose needs to rise up 4 or 5 inches before bending down into the washing machine. You may need to use a cable tie to fix it into the correct position.
If the drain hose pumps into a stand pipe
If your washing machine does not pump out into the U-bend, it may be pushed into a larger stand pipe. So you shouldn’t get this fault. There are rare circumstances where water could be sucked back into the machine, though.
For example, if the stand pipe outside is submerged in water through a blocked grate, and the drain hose is sealed into the standpipe with tape, instead of sitting in it with an air gap around it. (Check the drain hose is installed properly).
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