The short answer
On a built-in column the water is nearly always frost that entered as room air, so the door seal leads before the drain does. Ranked first on this platform: Humid air entering past the seal. The checks below follow that ranking, and the first of them need no tools and no panel removed.
What you observe
- Frost heaviest near one part of the door, and water appearing after each defrost — The frost pattern points at the leak; the timing points at the defrost.
- A sheet of ice across the floor of the cabinet under the baskets — Ice on the floor of a freezer is water that could not get out.
- Water at the front of the cabinet and a door that swings open on its own — The door behaviour and the wet floor share one cause.
- NEAR MISS — the outside of the cabinet is wet rather than the floor — Condensation on the shell is a humidity and seal question rather than a drain one.
Causes, most likely first on this platform
- Humid air entering past the seal — Every cubic metre of room air that gets past the seal leaves its moisture behind as frost. It ranks first on this platform because every cubic metre of air that gets past the seal leaves its moisture behind as frost, and in a built-in installation the volume of air moved each time a drawer is opened is enough to overwhelm a drain that is working perfectly.
- A blocked defrost drain — A frost-free freezer melts its coil clear on a schedule, and every drop of that water leaves through one small trough and one small hole. It ranks second here because the appliance is built into furniture, so the housing, the clearances and the alignment the fitter left behind are part of every fault it produces.
- The cabinet tilted forward — Drains and troughs assume the cabinet is level or tipped very slightly back. It sits third because the causes above it account for more of these cases, not because it is unlikely.
Check in this order, and why
- Run a slip of paper round the seal and find where it comes out freely — Two minutes with no tools, and it maps the whole door. It leads because it tests the top-ranked cause.
- Take the bottom basket out and look at the floor and the trough at the back — It locates the fault inside the cabinet without tools. Tests the second-ranked cause.
- Put a spirit level on top, front to back — Two minutes, and it saves a wasted parts order. Tests the third-ranked cause.
What an owner can safely check
- Wash and dry the gasket, then check the hinges for droop and repeat the paper test — A dropped door gives the same reading as a dead gasket and costs nothing to correct.
Tools: clothAbout 25 min
- Defrost the cabinet fully, then flush the drain with warm water from inside — Warm water rather than anything stiff — the tray behind it punctures easily.
Tools: warm water, towelAbout 40 min
- STOP here if the next step needs a meter on live terminals or a sealed panel off — That is where an owner check ends. Write down what each check showed and hand it to the technician.
Before you start tracing it
Safety
Unplug the appliance or switch off its breaker before removing any panel or reaching into the base — a capacitor can hold a charge after the power is off, and water in a live machine compartment is the one combination that deserves real caution.
When to call a technician
Call when the drain will not clear from the cabinet side, when the water is coming from behind a sealed panel, or when a defrost fault is putting more water into the cabinet than the drain was ever meant to carry.
Nearest pages of this class
What this page does not cover
This page is written for the Miele freezer as a class, not for one family or one model line. Where a family- or model-specific page exists for your unit, that page is the more specific answer and the one to read first. Deliberately not here: part numbers, wiring colours and disassembly order, which differ by family.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
