A washing machine leak not only creates a mess inside the house but can also damage internal components like tub bearings. Where the leak occurs at the bottom of the washing machine and only during the filling cycle, it’s often easy to locate the root cause.
Your washing machine may leak from the bottom during the fill cycle due to a faulty water inlet valve or damaged supply hoses. Make sure the connections are tight and consider replacing the inlet hose. The second most likely cause is a faulty water level switch which causes an overfilling of water.
Within this article I’ll take you through the most common causes of leaks during the fill cycle, starting with the easiest to diagnose and fix. I’ve also provided instructions on how you can fix these issues from home.
Why Is Your Washing Machine Leaking from Underneath When Filling Up? 6 possibilities
When your washing machine leaks from the bottom during the filling cycle, there are a few specific and common causes that I’m going to run through. You may also notice that the washing machine only leaks during the fill cycle and does not leak during other cycles, like the rinse.
I personally own a stacked washer and dryer making it difficult to access certain parts of the washing machine. If you’re the same, you might want to also read my article on moving the leaning tower of washer/dryers once you’ve figured out the problem!
Fortunately, many of these problems are easily fixable at home:
1. faulty water inlet valve or damaged supply hoses
The number one most common cause of a washing machine leaking during the fill cycle is faulty inlet hoses. The inlet hose on a washing machine supplies water from the main water supply to the machine, allowing it to fill with water before starting the wash cycle.
Missing gaskets or loose connections will cause water to leak and pool on the floor during the fill cycle. Sometimes the inlet valve also malfunctions (which controls the flow of water into the washing machine) causing it to not close properly, and therefore leakage during the fill cycle.
So the first thing you should do is tighten these connections and replace damaged or missing gaskets and washers to stop the leak. Inspect the water inlet valve at the back of the machine by checking for any signs of damage (cracks or leaks). Momentarily turn on the water supply and look for any water drips or leaks. Also, examine the supply hoses for things like cracks or moisture.
My recommendation as the easiest way to fix a leaking inlet connection is to simply replace the hose with some universal hoses like these (on Amazon). They are cheap and easy to replace.
GE Appliances actually recommends you change the fill hose screens and washers (on Amazon) every five years to prevent leakages.
2. pressure switch (water level switch)
The second most common cause of a leak from the bottom of a washing machine during the fill cycle is a faulty pressure switch. The pressure switch in a washing machine plays a crucial role in managing water intake during a fill cycle. When you start a wash, it instructs the water inlet valve and temperature switch to fill the tub.
With a functioning pressure switch, the water inlet valve should turn off at the correct water level and instructs the machine to begin agitating.
If the water level switch is faulty, your washing machine’s tub can overfill and leak during the fill cycle. You might also experience your washer stopping mid-cycle, or not even starting at all.
To test a washing machine water level switch follow these instructions:
- Locate the pressure switch. In front-load washers the switch is normally directly under the top panel, often attached to the frame. For top-loaders, you’ll find the switch in the interior of the washer panel under the main top, or behind the control panel.
- Remove or isolate the pressure switch and the attached air pressure tube.
- Inspect the air pressure tube and confirm it has no cracks or holes, and that it fits snugly into the switch port.
- Figure out which terminal is which on the switch using your washer wiring diagram. There are 3 terminals – ‘common’, ‘normally closed’, and ‘normally open’.
- Use a multimeter (on Amazon) to test the switch for continuity. Rotate the multimeter selector to the lowest level of ohms of resistance.
- Connect the black lead to the ‘common’ terminal and the red to the ‘normally closed’ terminal.
- Read the meter display which should show close to 0 ohms. Then blow into the pressure tube and watch the display on the multimeter. You should hear a clicking sound and the display should show resistance.
- Repeat the same process for the ‘normally open’ terminal.
If your switch ohm reading remains negative throughout this entire test, or shows a positive reading when it should not, your pressure switch will need replacing.
Negative throughout the test or positive when it should not, you know it needs replacing. Pressure switches cost upwards of around $20 and are not too difficult to replace. Here’s a video I found showing the replacement of an LG/Kenmore pressure switch:
3. clogged or overflowing detergent drawer
Another potential cause of water appearing at the bottom of your washing machine during the fill cycle relates to a faulty detergent drawer. If your soap drawer only leaks when the washing machine is filling, it’s possible your water pressure is too high.
The first thing you should do is make sure your washing machine is level. A washing machine that leans forwards encourages water to leak from the detergent tray.
Next, make sure your detergent dispenser is not clogged. Give it a good clean, ensuring you remove all excess detergent. Run water through the dispenser to check if it flows freely without any leaks.
Note: you should also leave your drawer open to air dry once the cycle is finished. This will prevent mold buildup.
Lastly, consider reducing the water pressure by turning the tap on the washer down as some soap dispensers can’t cope with high water pressure.
4. unlevel washing machine
Another basic check you should carry out whilst investigating the cause of the leak is to ensure your washing machine is properly balanced. An unbalanced washing machine can cause the following problems:
- Leaks
- Excessive vibrations or shaking, particularly during the spin cycle
- Loud banging noises
- The machine ‘walking’ or moving across the floor
Additionally, if your washing machine isn’t sitting level, water can splash off the top of the basket or load over the tub as it fills. This may leak onto the floor.
Balancing a washing machine is easy:
- Place a level across the front and back of the machine to check its level. You can also push the two corners of the top of the machine to detect any unlevel legs.
- Adjust the feet at the base of the machine until you achieve level.
5. cracked drain pump
Whilst the washing machine drain pump is inactive during the fill cycle, a cracked drain pump can cause water to leak from the bottom while filling. The washing machine’s pump normally has two or three black hoses connected to it and spins via a drive belt. If any of these parts are causing a leak, it’ll often be most noticeable whilst the tub is filling or is full of water.
The drain pump is typically located at the bottom of the washing machine, near the rear or side of the unit. So it makes sense to find water at the bottom of your washing machine if it is faulty.
You’ll normally notice other signs with a cracked drain pump:
- Water leakage or puddling around the drain pump
- Abnormal noises during draining
- Failure to drain all the water properly after the wash cycle
Whilst any washing machine can technically suffer from a cracked drain pump, I’ve read that Whirlpool top-loading washers are particularly susceptible to this problem.
6. tub seal leak
The tub seal in a washing machine is located between the outer tub and the inner tub, sealing the two parts together to prevent water leakage during the wash and spin cycles. It also prevents oil and other nasty substances from entering your drum. If it leaks, water will appear near the center of the bottom of the outer tub.
A damaged or torn sub seal can cause a small leak during the filling cycle, which you might be experiencing. You may also notice oil leaks and oil getting on clothes in addition to a grinding or scraping sound whilst the machine is running.
Eventually, a leaking tub seal will rust your tub bearings leading to a loose washing machine drum.
Replacing the tub seal kit isn’t a massive job but it will take a bit of elbow grease and an hour or so of your time. The process will vary based on your model. You can opt for a simple repair using a “tub seal” kit like this one (on Amazon). Note: you’ll need to find a seal kit specific to your model.
Here’s a great video I found on how to replace a tub seal kit in a top-loading washer:
