The short answer
On a Kostch dishwasher, water on the floor is most often feet that have dropped since installation. Run a cycle with paper under the machine and watch where it wets first — that single observation halves the list below before any tool comes out.
The symptoms, and the ones that mean something else
- Water appearing at the front, under the door — Water travels along the base plate, so the front is where most leaks appear regardless of where they start.
- A leak that only happens on full loads — Overfilling, or an item deflecting spray straight at the door seal.
- A damp patch on the floor that appears hours later — A slow drip from a fitting collecting on the base and finding its way forward.
- NEAR MISS — the water is coming from the sink waste, not the machine — Check the trap and the waste connection under the sink first: a leak there wets the same floor and has nothing to do with the dishwasher.
The ranking, and why it is this way round
- Feet that have dropped since installation — A dishwasher relies on being level to keep its water where it belongs. Tilted forward, the wash water sits against the door seal instead of draining back to the sump, and the seal loses an argument it was never meant to have. Ranked ahead of the rest since it is both the likeliest and the only one that can be settled before anything is taken apart. Documentation is thin on a brand like this, so the ranking leans on what can be observed directly rather than on a schematic.
- A door that no longer closes square on its seal — A door that has dropped on its hinges, or a machine that is no longer level in its housing, puts uneven pressure on that seal, so the leak appears at one corner rather than all round. It follows the first because the two produce the same complaint, and this one is the cheaper of the pair to eliminate.
- Inlet or drain hose connection weeping — This ranks where it does because the check is simple — paper under the machine and a torch — but it needs the machine eased out, which is a step beyond the door and the detergent. It sits here because it is a genuine cause with a narrower set of circumstances behind it.
- A cracked tub or a failed seal under the machine — A genuine crack in the tub is rare and usually the result of something heavy being dropped or a fixing over-tightened, but it does happen and it is the one cause here that can end a machine. Last, because the three above explain most of what actually comes in on this fault.
The order that finds it fastest
- Check each foot is taking weight and the machine does not rock — A machine rocking in its housing works its door seal every cycle. Begin with this one; everything after it depends on what you find.
- Shut the door on a strip of paper at several points and pull — Uneven resistance around the door shows where the seal is not being loaded properly. Second, and still no tools beyond a torch.
- Lay dry kitchen paper under the machine and run a full cycle — Where the paper wets tells you whether the source is at the front, the back or the middle. Third, and the last thing worth doing before the phone comes out.
What to do, step by step
- Adjust the levelling feet until the tub base reads level and the machine sits firm — Adjust in small steps and re-check with the door open and shut.
Tools: spirit level, adjustable spannerAbout 30 min
- Clean the gasket and the door edge with hot soapy water and dry it — Work right into the channel; that is where the grease collects.
Tools: cloth, detergentAbout 20 min
- Tighten the drain hose clamp at the waste connection — Snug is enough; over-tightening a plastic spigot cracks it.
Tools: screwdriverAbout 20 min
- STOP at the point where a panel has to come off to go further — Everything past that point is measured, not looked at, and measuring means live terminals. Book the visit instead.
Read this before you start
Safety
Switch off at the socket or isolator first; a capacitor and mains terminals sit behind the door panel. Use a glove and a torch rather than bare fingers when clearing a sump, and never mix cleaning chemicals in the tub while looking for a smell.
When to stop and call
Call once the door seal is clean and sound, suds are ruled out, the machine is level and the connections are dry — a leak that survives all four is below the tub, and that means the machine out and the pump housing opened.
Other pages for this dishwasher
Scope, and what is missing from it
This page is deliberately generalized across the Kostch dishwashers it covers. It does not carry model-specific wiring, torque values or component resistance figures — those belong on the page for your family, and that page takes precedence where it exists.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
