The short answer
Where the puddle appears tells you where water leaves the machine, which is not where it started. Work from the sources rather than from the floor, and the diagnosis takes minutes rather than an afternoon. On the RBM models the defrost drain and the supply connection sit at opposite ends of the cabinet, so establishing which one you have before moving anything saves the whole second half of this list.
Where the water shows up
- Water running down the inside back wall — Water running down the inside back wall is either condensation or defrost water that has lost its path. Separate it from a supply leak before moving anything.
- A wet patch only after the ice maker fills — Timing tied to the fill cycle is the clearest evidence there is that the water is arriving rather than escaping.
- Damp or buckling flooring in front of the machine — Flooring that has darkened or lifted means this has been running a long time. Stopping it matters more than identifying it perfectly.
- NEAR MISS — Water inside but the cabinet has also gone warm — Water inside a cabinet that has also gone warm is melting food, not a leak. Fix the cooling fault and the water stops.
What is behind it, ranked
- Door seal letting warm humid air in — Warm room air meeting cold surfaces condenses. A gasket that has hardened or a door left ajar puts a surprising amount of liquid water inside a cabinet over a day. It goes first because if it is not this, the remaining list is short and much easier to work. Against the brand-wide ranking, door seal letting warm humid air in has moved up past the ice maker fill system overfilling or misaligned on this platform.
- A blocked defrost drain — It recurs if only the visible ice is cleared: the plug is usually further down the tube than it looks.
- The water supply line or its fittings — Supply leaks give clean water, often at the back and often growing rather than coming and going. That pattern separates them from defrost water immediately.
- The drain pan cracked, dislodged or overflowing — It is easy to check at the same panel as the drain outlet, which is why it sits near the drain in this order.
Check in this order, and why
- First — test the door seal and look for sweating inside — Paper-test the gasket all the way round and look for condensation on the inner walls. Water plus frost is an air-leak story rather than a plumbing one. The order separates clean water from defrost water and inside from outside before anything is dismantled, because those two distinctions decide the repair.
- Second — look for water under the crispers and ice on the freezer floor — Take the bottom drawers out and look underneath, then look at the freezer floor. Water or ice at either point sits directly below the drain that should have taken it.
- Third — check the supply line and its fittings at the back — With the machine pulled out and the house valve shut, run a dry tissue around each fitting and along the line. Clean water at a fitting is a supply leak and it will not stop on its own.
- Fourth — find the drain pan above the compressor and look at it — With the power off, find the pan above the compressor and check it is clipped in, intact and not brimming. A pan holding far more than usual points back at the defrost system.
Safety first
Safety
Disconnect the power before reaching behind the grille, and close the supply valve before disturbing the line. Wet hands, a metal chassis and a live compressor circuit are a bad combination, and a supply line under pressure can empty a great deal of water into a kitchen very quickly.
When this stops being a homeowner job
The owner line is the panel and the fitting. Flushing a drain from inside the compartment, reseating a pan, levelling the cabinet and switching the ice maker off are yours; removing the freezer rear panel to reach a plugged drain or replacing a valve is not.
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Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
