Water in a washer drain pan almost always comes from one of four places: the fill hoses, the drain hose or standpipe, the washer itself, or condensation on cold pipes. Upstairs laundry, common in colonials and newer builds, puts a ceiling under that pan, so it pays to find the source before the next load.
Safety first: Unplug the washer and close both water valves before you pull it out, and keep electrical cords and outlets clear of standing water.
Follow the diagnostic path
Step 1: Is there water in the pan even when the washer hasn't run?
If yes: Something under constant pressure is dripping: a fill hose, its washer, or the valve. Wrap a dry paper towel around each connection and check it after an hour. In humid summer weather, sweating cold-water pipes can also drip into the pan.
If no: Go to Step 2.
Step 2: Does the pan fill only while the washer drains or spins?
If yes: Look at the standpipe. If water backs up and spills over the top, the drain line is partly clogged and a plumber should clear it. Also check that the drain hose is secured and not pushed deeper into the pipe than the manual allows. A slow drain can also make a washer stop mid-cycle.
If no: Go to Step 3.
Step 3: On a front-loader, does water collect under the door?
If yes: Check the rubber door boot. Hair, coins and lint caught in its fold can hold the seal open; clean it out. A tear in the boot needs a replacement part.
If no: Go to Step 4.
Step 4: Does water show up under the washer while it fills or washes?
If yes: The leak is inside the cabinet: an internal hose, the pump or a tub seal. That's a technician job.
If no: Go to Step 5.
Step 5: If your pan has a drain fitting, does water drain out of it?
If yes: The pan is doing its job; keep watching for the source.
If no: A clogged pan drain lets small drips build up. Clear the fitting, or have a plumber check where the line runs.
What your answer points to
| What you found | Most likely cause | DIY or technician |
|---|---|---|
| Water with the washer idle | Fill hose or valve drip | DIY hose swap; plumber for valves |
| Water only during drain | Standpipe backup or loose hose | DIY hose fix; plumber for the drain |
| Water under the door | Dirty or torn door boot | DIY cleaning; technician for a tear |
| Water from underneath mid-cycle | Pump, internal hose or tub seal | Technician |
| Slow buildup, pan drain dry | Clogged pan drain | DIY or plumber |
Stop and call a technician if
- •Water appears from under the cabinet while it runs.
- •You find water stains on the ceiling below.
- •The washer shows a leak or drain error that returns.
Keep it from coming back
- •Replace fill hoses at the interval in your manual, and sooner if they bulge.
- •Put a battery leak sensor in the pan.
- •Close the washer valves when you're away for more than a few days.
Owen's shop tip: In upstairs laundry rooms, I always pull the washer out far enough to see the hose ends. More pans fill from a tired hose washer than from the machine itself.
If the water is coming from inside the cabinet, book a visit through our washer repair page or call (617) 812-1425, and keep the valves closed until then.