The short answer
On the COSDWC family the usual reason a Cosmo dishwasher is leaking water is machine tilted forward, and that is where the order below departs from the brand-generic article one level up: on the integrated build carrying a cabinet door it outranks sump or wash-pump seal. The check that confirms which build you have is simple — a furniture panel screwed to the machine door means extra weight on the hinges and a door that can sit a fraction proud. The gasket, the loading, the detergent and the levelling are owner work; the sump seal and the inlet valve are not.
What you observe on these models
- Water under the centre of the machine — Away from the door, which moves the question to the sump.
- A puddle under the sink rather than the machine — The drain joint, which sees water only at the drain step.
- Water at the front, under the door — The classic seal or tilt presentation, and both are checkable in minutes.
- Foam visible through the door near the end — Chemistry rather than mechanics, and instantly reversible.
- A leak that happens on some loads and not others — Follows the load rather than the machine, which points at spray deflection.
- NEAR MISS — water standing inside the tub instead — That is a drainage fault and the drainage page is the right one.
Causes, most likely first on the COSDWC family
- Machine tilted forward — Ranked first here: these machines are meant to sit level or very slightly back. Tipped forward, the tub carries water to the door on every wash and the seal is asked to hold back a standing level.
- Sump or wash-pump seal — Second: this is the first cause on the list that is a real repair.
- Overfill from an inlet valve that does not close — Third: a valve that weeps when the machine is idle slowly raises the level until the tub overflows at the door, usually overnight when nobody is watching.
- Door gasket not seating — Fourth: the gasket runs the whole way round the door and only has to fail at one point.
- Drain hose joint under the sink — Fifth: it is worth ranking because the puddle appears under the sink rather than under the machine, which sends people looking in the wrong place.
- Spray deflected past the door by the load — Sixth: it produces an intermittent leak that follows the load rather than the machine, which is exactly what owners describe as random.
Check in this order, and why
- Check the machine sits level or very slightly back — Tipped forward, the tub delivers water to the door every wash.
- Note whether water appears under the middle of the machine — Centre rather than front moves the fault from the door to the pump.
- Note whether water appears with the machine switched off — Only a weeping inlet valve fills a tub that is not running.
Before you open anything
Safety
Switch the machine off at its spur or unplug it, and shut the isolating valve under the sink, before anything is opened — water and mains wiring sit close together under this cabinet. Never defeat the door latch to watch a cycle run with the door open; that interlock stops a hot spray at head height. Bail standing water out before tipping the machine, and expect glass in the sump, so feel with a cloth rather than bare fingers. Get a second person before you pull the cabinet out or tilt it.
Models in the COSDWC family
Reference| Model number | Family key |
|---|---|
| COS-DWC24TTG | cosmo:dishwasher:cosdwc |
| COS-DWC24TTR | cosmo:dishwasher:cosdwc |
When to call a technician
Once the free checks are clean the remaining causes are the sump seal and the inlet valve, both of which need the machine drawn out and the power isolated. Shut the supply off first, then call.
