The short answer
A Caf ZDT dishwasher that will not empty is either not being told to drain, not able to drain, or pumping into a blocked path. The matrix below carries a single model tag, so there is no revision fork to work around on this family: what holds for that tag holds for the line. Listening at the end of the cycle settles which: a pump that hums without moving water is a very different fault from silence.
What you can observe on these models
- Glass or a fruit stone visible in the sump — The direct cause, and the reason a drain fault can appear overnight on a machine that was fine.
- Dirty water standing in the tub at the end of the cycle — The wash completed and the drain did not. That points at the drain path rather than at the wash system.
- A hum at the drain step with no water movement — The pump is being driven but cannot turn, which is the signature of a jammed impeller or a solid blockage.
- Silence at the drain step — No pump drive at all — a control, a wiring or a pump motor fault rather than an obstruction.
- NEAR MISS — water on the floor rather than in the tub — That is a leak, and the leak page covers it. A machine can leak and drain perfectly well at the same time.
Causes, most likely first on this family
- Filter, sump and the pump inlet — First because it is where everything the machine washes off ends up, and because a five-minute clean resolves the majority of these calls.
- Drain pump impeller obstructed by glass or a stone — Second, and the natural next step once the filter has been cleared and the fault persists.
- Air gap or disposer connection blocked — Third: the machine pumps fine and the water has nowhere to go, which presents as backflow on the sink deck rather than as a still tub.
- Drain hose routing and the high loop — Fourth, and settled by looking behind the machine rather than inside it.
- Control board, door latch signalling or pump motor — Last: an aborted cycle looks like a drain failure but is a control fault, and both need a technician to separate honestly.
Check in this order, and why
- Confirm the cycle actually reached the drain step — A cycle that aborted early leaves water behind without any drainage fault existing at all.
- Inspect the disposer connection for the knockout plug — On a recent installation this is the first thing to check and the fault is total until it is removed.
- Clear the filter and inspect for glass — Use a gloved hand. Glass in the sump is both the cause and the reason to be careful about how you clear it.
- Straighten and re-loop the drain hose — Give it the rise it needs behind the cabinet so the tub cannot siphon back after a good drain.
Before you open anything
Safety
Kill power at the breaker before any disassembly — a capacitor can hold a charge after the power is off. If the machine has to be pulled out, close the hot water shutoff under the sink first, support the door so it cannot drop, and watch for the drain hose catching on the cabinet as it moves.
Models in the ZDT family
Reference| Model number | Family key |
|---|---|
| ZDT98***N*** (v7) | caf:dishwasher:zdt |
When to call a technician
Scooping, filtering and hose routing are yours. Call for anything that needs the pump removed, the check valve replaced or the control condemned on these models. Call the same day if dirty water has reached the floor and run under the cabinet — the drainage repair is small and the cabinet damage is not.
Other faults covered for this family
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
