Supply Leak or Drainage Overflow?
Every appliance leak falls into one of two families. A supply leak is clean water arriving under pressure from a fill line, valve, or fitting, and it tends to keep coming whether the appliance is running or not. A drainage overflow is water the appliance already used backing up because a drain is blocked, a pump has failed, or a pan has cracked. Supply leaks call for shutting the valve; drainage issues call for clearing the path. Telling them apart early prevents both floor damage and unnecessary parts.
Most Common Causes
- Blocked defrost drain overflowing the internal pan in a refrigerator
- Cracked or overfilled drain pan under the unit
- Leaking water line or inlet valve to an ice maker or dispenser
- Worn dishwasher door gasket or spray arm deflection
- Failed dishwasher drain pump or a loose hose clamp
- Clogged filter forcing water past a dishwasher seal
- Condensation from a failing door gasket that mimics a leak
Notes by Brand
On Sub-Zero built-ins, a recurring puddle is often a blocked defrost drain or an ice maker fill line rather than the sealed system. Miele and Bosch dishwashers use a base tray with a float safety, so a leak can trip an E15-style shutoff before water reaches the floor. Cove dishwashers share that safety-tray design. Thermador and KitchenAid units more often leak at the door gasket or a spray arm seal. Viking refrigeration can leak from the water line behind the unit where it connects to the household supply.
Symptom-To-Cause Reference
| Where the Water Is | Likely Cause | Next Step |
|---|---|---|
| Puddle under fridge | Defrost drain or drain pan | Clear drain, replace pan |
| Water inside crisper | Blocked internal drain | Flush and clear drain line |
| Under dishwasher | Drain pump or hose clamp | Test pump, secure hose |
| From dishwasher door | Gasket or spray deflection | Replace gasket, check arm |
| Behind the unit | Supply line or inlet valve | Replace line or valve |
Shut the Supply and Protect the Floor
For any active leak, close the local shutoff valve and slide towels or a tray under the unit. Water reaching hardwood or cabinet bases causes damage fast, so treat a running leak as time-sensitive even if the appliance still works.
Book a Leak Diagnosis
Diagnostic and travel fees, if applicable, are confirmed before the appointment and before repair approval.