The short answer
Water on the floor under a Bosch SMS-series dishwasher is placed before it is fixed, and on this family the placing is easier than usual because its own worktop narrows the list straight away. Water at the front of the door is the seal, the door's own alignment or the dispenser; a machine that empties itself and then refuses to fill has found water in its own base pan and is telling you the leak is underneath.
What you observe
- A swollen cabinet edge or lifted flooring beside the machine — A slow leak that has been running longer than the puddle suggests.
- Suds creeping out along the bottom of the door — That is detergent, not a failed seal. The wrong product in the dispenser overwhelms the door seal.
- A wet patch directly in front of the door — Water that ran down the inner face of the door and over the lip. That is the seal or the door sitting proud.
- NEAR MISS - water only appears when the sink is used — That is the waste connection above the machine rather than the machine itself, and it is fixed under the sink.
Likeliest causes here
- The door gasket hardened, displaced or dirty — The seal only works while it is soft and seated all the way round, and a strip of grease along the bottom of it is enough to break the line. First on this family, and for a reason that belongs to the platform: it is the part of this machine that is handled most often and inspected least.
- Foam from the wrong detergent — Hand detergent or too much of a gel makes suds that climb past a perfectly good seal. Second here, and close enough behind the first to be checked in the same pass: it is the cause that leaves no trace once the floor is dried.
- The door sitting proud at one corner — Hinge cables and springs wear, the door stops closing square, and one corner of the seal never touches. Ranked third on these models: slow to develop and obvious once looked for.
- The dispenser housing or the rinse aid well — A cracked cup or an overfilled rinse aid well runs down the inside of the door and out under it. Last, and the ranking is the point: it leaves a clean run mark down the inner door, which makes it easy to confirm.
- Where this ranking departs from the brand-generic page — The cause that moves is the door gasket hardened, displaced or dirty. It leads on this family because the machine has its own worktop and is usually plumbed into a run that was already there. That is a property of the platform rather than of the brand, which is why the page above this one cannot rank it the same way.
Check in this order
- Run a finger all the way round the door seal — Feel for grease, hard spots and a strip that has crept out of its channel. Wash it and re-seat it before anything else.
- Read the label on whatever is in the dispenser — Anything not made for a dishwasher, or too much of the right thing, produces exactly this leak.
- Close the door on a sheet of paper at each corner — The paper should grip the same at all four. A corner that lets go is a door that is not sealing.
- Look for a clean run mark down the inner door — A track from the dispenser to the lip names the source without any tools.
Before you open anything
Safety
Shut the water off at the valve under the sink and unplug the appliance or switch off its breaker before removing any panel - a capacitor can hold a charge after the power is off, and on a leaking machine the mains connection is sitting in the wettest part of the cabinet. Dry the floor before you test anything, so the next drop you see is new.
When to call
The door seal, the dispenser, the rinse aid well, the detergent and everything under the sink are owner ground on these models. The line is the base pan: once the machine is emptying itself and refusing to fill, the water is beneath the tub and finding it means the machine on its back with the base plate off.
Nearest pages
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
