The Short Answer
Where the water lands rarely tells you where it started. A refrigerator leaking onto the floor is usually a defrost drain overflowing inside; a dishwasher puddle is usually the door seal or the sump; an ice maker leak is usually a line fitting or an overfilled bin. The job is to trace the water back to its source rather than treat the symptom, because a leak that keeps returning is a source that was never found.
Most Common Causes
- Clogged or frozen defrost drain. The most common refrigerator leak; melt water overflows the pan and runs out.
- Worn door seal. On a dishwasher it drips at the door; on a fridge it lets in moist air that condenses and pools.
- Cracked sump or hose. A dishwasher leak that shows up only during a cycle.
- Failed inlet valve. A valve that will not close fully weeps into the appliance.
- Ice-maker line fitting. A weeping compression fitting behind a refrigerator.
Notes by Brand
On Sub-Zero and Liebherr refrigeration, a frozen defrost drain is the classic leak, and a drain heater often prevents a repeat. On Cove, Miele, and Bosch dishwashers, the leak-detection tray will shut the machine down when it senses water, so a small door-seal drip can present as a dead dishwasher. On Thermador and KitchenAid units, we check the sump gasket and the drain hose routing. Across all brands, an ice-maker supply line is worth inspecting whenever water appears behind a refrigerator.
Symptom Reference
| What You See | Likely Cause | Fix |
|---|---|---|
| Water under the fridge | Clogged defrost drain or ice line | Clear drain, fit drain heater, seal line fitting |
| Water at the dishwasher door | Worn door seal | Replace gasket, reset door balance |
| Leak only during a cycle | Cracked sump or spray-arm gasket | Test under water, replace sump or seal |
| Dishwasher shows a leak code | Leak tray tripped by a small drip | Dry tray, find and fix the drip source |
| Puddle inside the fridge | Blocked internal drain | Thaw and clear the drain path |
Appliance Leaking?
Book a leak diagnosis. Diagnostic and travel fees, if applicable, are confirmed before the appointment and before repair approval.