The STW answer in short
A leaking Avanti STW washer is an urgent fault with a cheap cause more often than not. Turn the taps off, dry the floor, then run a short cycle and watch: where the first drop appears tells you which of the four usual suspects it is.
What you notice first
- Clean water at the back of the machine, even when it is off — On STW models, that is a supply-side leak at a tap or an inlet hose, and it will not stop on its own.
- Water appearing only during the drain or spin — Across the STW line, timing the leak to the drain step narrows it to the pump side of the machine.
- Water only during the spin — Within the STW family, timing the leak to a stage of the cycle is the single most useful observation here.
- Water tracking along the floor from behind the machine — Looking at STW models specifically, follow the trail to its top before concluding anything.
- Soapy water at the front during the wash — Looking at STW models specifically, a door seal or a detergent dispenser overflowing, both of which show only under load.
- NEAR MISS — damp only inside the door seal after a wash — A little water trapped in the seal fold is normal. Wipe it dry and leave the door ajar between washes.
What actually fails on STW models, in order
- An inlet hose or tap connection weeping — It leads because a supply leak is both the most common and the most damaging — it runs whether the machine is on or not.
- Too much detergent, or the wrong type — It belongs on the list because it is free to test: one short cycle with a correct dose settles it. On the STW models below the ranking is the same.
- An overloaded drum forcing water past the seal — A drum packed past the point where the load can tumble pushes water into the door seal under spin pressure.
- A split sump, bellows or internal hose — It comes last because everything above leaks in the same place first, and because this one is a technician job. Nothing in the STW line changes that order.
Where to start, and what follows
- Turn the taps off and see whether the water stops — Looking at STW models specifically, do this first if the water is clean and the machine is idle.
- Run a finger round the door seal channel — Wipe it out, check for tears at the bottom of the fold, and dry it.
- Run one cycle with a correct detergent dose — Use the right product for the machine type and measure it rather than guessing.
- Close both supply taps and see whether the water stops — Where STW models are concerned, do this first whenever the water is clean and the machine is not running.
Before you begin
Safety
Isolate the machine and close both taps before you touch any fitting; a capacitor can stay charged after the power is off. Never chase a leak with the machine running and panels off. Dry hands, dry floor, and leave every door and lid proof circuit exactly as the maker built it.
Models in the STW family
Reference| Model number | Family key |
|---|---|
| STW16D0W | avanti:washer:stw |
| STW20D2P | avanti:washer:stw |
| STW30D0W | avanti:washer:stw |
When this stops being an owner job
Call when the hoses, the filter cap, the door seal and the dosing are all sound and water still appears, or when the leak is plainly coming from inside the cabinet. Call immediately if water has reached a socket or the control panel — that is an electrical hazard rather than a plumbing nuisance.
Other faults on the STW line
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
