The short answer for DWT models
On the DWT line a drainage fault has a clear order to it. Clear the filter and the sump first because they are free, then the hose and the household connection, and only then treat the pump as a suspect. The pump is the last thing to fail and the first thing owners blame.
What the owner sees
- A humming at the drain step with nothing moving — The pump is being asked to run against a blockage.
- The problem appeared right after a new waste disposer was fitted — The knockout plug, almost every time.
- A cycle that stops partway and shows a fault — Many machines abort when they cannot verify the water has gone.
- Silence at the drain step — The pump is not being driven at all, which moves the fault to the electrical side.
- NEAR MISS — the dishes are dirty but the machine drains — That is a cleaning fault and belongs on that page.
Causes on DWT, most likely first
- Filter and sump packed with food waste — Ranked first because it is the commonest and the only one the owner is asked to maintain.
- Waste disposer knockout plug still in place — Second and the reason a machine that drained yesterday does not today: fitting a disposer without removing the plug seals the drain completely.
- Check valve stuck — Holds water in the machine or lets it back in, depending on which way it sticks.
- Foreign object in the pump — Glass fragments, fruit stones and bones all reach the impeller once the filter is full.
Check in this order, and why
- Where to begin — The order below follows the ranking rather than the machine: two of the four causes above cost nothing to rule out on DWT models, so they come first.
- Pull the machine out and follow the drain hose for kinks — It gets pinched against the wall or a cabinet foot whenever anything is moved.
- Listen at the drain step and decide between a hum and silence — A hum is a blocked pump; silence is a pump not being driven.
- Ask whether a waste disposer was fitted recently — If yes, check the knockout plug before anything else on this list.
Isolate both services first
Safety
A dishwasher has two services to isolate and both matter: the breaker or the plug for the electricity, and the supply valve under the sink for the water. A capacitor can hold a charge after the power is off. Let the machine cool before reaching into the sump, because the element there holds heat for a long time after the cycle. Never run a cycle with the door interlock defeated.
Models in the DWT family
Reference| Model number | Family key |
|---|---|
| DWT18V3S | avanti:dishwasher:dwt |
When to call a technician
The boundary on this machine is the base panel and the sump cover. Filters, spray arms, seals, hoses, loading and detergent are all yours. Anything that needs the machine out and a panel off is a service call, and so is any fault that has tripped a breaker.
Other DWT problems we cover
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
