A washer that drains while it's filling is usually siphoning: the drain hose is pushed too far down the standpipe, sealed in tight, or connected to a drain that sits too low, so gravity pulls water out as fast as it comes in. Repositioning the hose fixes most cases, but a pump or water level sensor problem can cause a similar symptom.
Quick diagnosis
| Symptom | Likely cause | First thing to try |
|---|---|---|
| Water running into the standpipe during fill | Hose pushed deep or sealed tight in the standpipe | Pull the hose up so only the end sits in the pipe, with room for air around it |
| Washer never reaches its fill level | Siphoning or a water level sensor problem | Fix the hose position, then retest |
| Hose runs to a low floor drain or laundry sink | Drain point below the washer's water level | Route the hose with a high loop per the manual |
| Water trickles out after the cycle ends | Siphon still running | Correct the hose position right away |
| Clothes barely wet and cycles run long | Water lost during the fill | Same fix as above |
| Drain pump hums during the fill | Pump running when it shouldn't | Stop the cycle and have it checked |
A closer look
How siphoning works
Once water starts flowing down a hose that ends below the level of the water in the tub, it keeps flowing on its own. The washer sees the level isn't rising and keeps filling, so you get a machine that fills and drains at the same time.
The standpipe and hose
Washer installation guides list how high the standpipe or drain point should be and how far the hose should go in. Those numbers vary by model, so check yours. The hose end needs air around it. Tape or foam stuffed around the hose to stop splashing can seal the pipe and start a siphon. Most washers come with a U-shaped hose guide that holds the hose at the right height.
The water level sensor
Many washers use a pressure sensor connected to the tub by a small tube. If that tube clogs, kinks or leaks, the control can misjudge the water level, filling too little or too long. That needs a technician.
Pump or control faults
Less often, the drain pump runs when it should be off. If you hear it humming during the fill with the hose correctly placed, stop the cycle.
Who runs into this most
New installations, laundry closets where someone taped the hose into the standpipe, washers that drain into a laundry sink or floor drain, and machines that were recently moved.
Prevention checklist
- •Use the hose guide that came with the washer
- •Never seal the hose into the standpipe
- •Recheck the hose position after moving the washer
- •Keep the standpipe clear so it doesn't back up
Time to call a pro
- •Water keeps flowing in with the hose correctly positioned (close the supply valves)
- •The tub overfills or water spills from the door or lid
- •The drain pump runs during the fill
- •A fault code appears (codes vary by model)
Travis's rule of thumb: The drain hose should rest in the pipe, not be packed into it. Give it air and most siphons stop.
Hose fixed and the washer still won't hold water? Book through our washer repair page or call (832) 552-1615. If the level now looks low but steady, check how much water an HE washer should use.