The short answer
A SMS dishwasher that leaves water in the tub has lost its drain path somewhere between the sump and the sink. The sixteen codes in the table cover more than one build generation, so match your own code against it before a panel comes off.
What you observe on these models
- Clean water standing in the sump after every cycle — Clean water means the wash finished and the drain failed at the end.
- The machine hums at the end of the cycle but the water level does not move — The pump is being asked to run and cannot turn, or it turns against a blocked outlet.
- The cycle stops part way and the panel shows a fault — Most controls abort the cycle once the water is still there after a drain attempt.
- Water comes back into the tub after the cycle ends — That is siphoning: the drain hose has lost its high loop or the air gap is blocked, and sink water is finding its way back in.
Causes, most likely first on the SMS family
- The filter and sump are packed with soil — First on this family, because the filter is the last thing between the food and the pump and the only part of the drain path an owner can reach without a tool.
- The drain hose is kinked, trapped or has lost its high loop — A hose crushed behind the machine when it was last pushed back, or one that has slipped out of its clip under the sink, produces exactly this symptom and leaves no trace inside the machine.
- The drain pump impeller is jammed by debris — Moved up on a family whose codes cover several generations: years of glass chips and fruit stones find the impeller eventually, and the hum-without-flow symptom is its signature.
- The air gap on the counter is blocked — Where one is fitted, it silts up with the same soil the filter caught.
- The drain pump has failed electrically, or the control is not calling it — Last, because it is the only candidate that cannot be cleared by hand and the least common of the six.
Check in this order, and why
- Run the drain or cancel function first — It forces one clean drain attempt with nothing else happening, so you can hear whether the pump runs, hums or stays silent.
- Bail the tub out and pull the filter — Scoop the standing water with a cup and a towel, then twist the filter out and look in the sump with a light.
- Check the sink side before the machine side — Run the disposal, check the hose behind the cabinet for a kink, confirm the hose rises into a high loop or air gap, and clear the air gap cap if one is fitted.
- Free the hose where it leaves the machine — The crush point is almost always where the hose passes the cabinet wall or sits behind the machine after it was last pushed back into place.
- Stop here if the pump is silent — A drain step that produces no sound at all, with a clear filter and a clear hose, is an electrical fault at the pump or the control — and that is where the owner-side list ends.
Models in the SMS family — Each code here is pinned to a single build, so match the tag inside your door frame character for character. The sixteen codes fall into seven leading groups, and that spread is the reason this page is written for the family rather than for one machine.
Reference| Model number | Family key |
|---|---|
| SMS24AI01A | bosch:dishwasher:sms |
| SMS26AI03A | bosch:dishwasher:sms |
| SMS2ITI02A | bosch:dishwasher:sms |
| SMS2ITW01A | bosch:dishwasher:sms |
| SMS4HTI01A | bosch:dishwasher:sms |
| SMS4HVB01A | bosch:dishwasher:sms |
| SMS4HVI01A | bosch:dishwasher:sms |
| SMS6HAI01A | bosch:dishwasher:sms |
| SMS6HAI02A | bosch:dishwasher:sms |
| SMS6HCB01A | bosch:dishwasher:sms |
| SMS6HCB02A | bosch:dishwasher:sms |
| SMS6HCI01A | bosch:dishwasher:sms |
| SMS6HCI02A | bosch:dishwasher:sms |
| SMS6HCW01A | bosch:dishwasher:sms |
| SMS88TI01A | bosch:dishwasher:sms |
| SMS8EDI01A | bosch:dishwasher:sms |
Before you open anything
Safety
Kill the power at the breaker before your hands go into the sump or the toe-kick comes off — you are working in water, and a capacitor can hold a charge after the power is off. Bail first so you can see: glass chips sit under the filter where nobody expects them.
When to call a technician
The owner side of this fault ends at the pump inlet. Filter, sump, drain hose, air gap and disposal are all reachable with a towel and a torch, and they account for most of these calls.
Other symptoms covered for this family
SC
Sarah Chen
Lead Appliance Repair Technician · 12 years experience
EPA 608 UniversalNASTeC Certified
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
