The short answer
This machine is connected and disconnected constantly, so its leaks are at the joints people make rather than at the ones the factory made. Ranked first on this platform: The faucet adapter. The checks below follow that ranking, and the first of them need no tools and no panel removed.
What you observe
- Water at the sink rather than under the machine — Position separates the adapter from everything inside the appliance.
- Water at the front of the machine while it runs, and a dry floor at rest — Leaking only while running is a running-water path.
- The leak only happens on cycles where the tank was topped right up — A leak that depends on what you poured in is about what you poured in.
- NEAR MISS — water on the floor when you open the door at the end — Water running off the door and the racks when a cycle finishes is normal, particularly on a machine that is not standing level.
Causes, most likely first on this platform
- The faucet adapter — A portable machine connects to the tap through a quick adapter, and that adapter is the single most common source of water on the floor. It ranks first on this platform because the faucet adapter is the single most common source of water on the floor with a portable machine: it is remade by hand every use, it carries full mains pressure, and its washer perishes long before anything inside the machine does.
- The door seal — The seal runs round the door and takes every knock from loading. It ranks second here because the machine is moved, which means every hose and every connection is disturbed regularly rather than fitted once.
- The internal tank overfilled — A machine that fills from a reservoir you pour into will take more than it can hold if you keep pouring. It comes third in the order — a genuine cause here, behind the ones above it on frequency alone.
Check in this order, and why
- Look at the adapter at the tap while the machine is filling — It is the one connection that is remade every single use. It leads because it tests the top-ranked cause.
- Run a finger round the whole seal and look for splits, hardening and debris — Two minutes with a torch and it finds most door leaks. Tests the second-ranked cause.
- Fill to the marked level rather than to the brim — The mark is there for exactly this reason. Tests the third-ranked cause.
What an owner can safely check
- Disconnect, check the washer inside the coupling, and refit it fully home — Replace a perished washer rather than tightening harder.
Tools: clothAbout 15 min
- Clean the seal and its channel, and check the door closes evenly at top and bottom — A door that is not square loads one part of the seal and not the rest.
Tools: cloth, torchAbout 20 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 machine or switch off its breaker before removing any panel, and close the supply valve. The fill connection is under mains pressure whether the machine is running or not, which is why the valve is shut before anything else.
When to call a technician
Call when the water is coming from the tub, from a seam, or from a component behind the panel, because those are strip-downs. Call immediately, having shut the supply valve first, if the leak is at the fill connection — that water arrives under pressure and does not stop when the cycle does.
Nearest pages of this class
What this page does not cover
This page is written for the MST dishwasher 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.
