The short answer
On Big Chill DWT models a dishwasher that has stopped cleaning is nearly always failing to get water where it needs to go, not failing to wash: blocked spray jets, a filter full of debris, or a load packed so the arms cannot turn. Which of those leads depends on whether your machine has a lift-out filter or a grinder. The first three checks below take a few minutes and no tools. On the DWT models the check that decides the order below is which build you have: a machine plumbed in under the counter, or not.
What the owner actually sees
- Sandy residue after a full cycle — It is often worse on the upturned items in the top rack.
- A cloudy film on glassware — A film you can rub off is deposit; one you cannot is etching and is permanent.
- Detergent still sitting in the dispenser at the end — Either the cup is blocked by a tall item or the water is not warm enough to dissolve it.
- The bottom rack is clean and the top rack is not — A rack-level split points at the arm feeding that rack or the feed tube behind it.
- The spray arms do not spin freely by hand — An arm that cannot turn cleans a stripe and misses everything else.
- NEAR MISS — dishes come out clean but wet — That is a drying and rinse-aid question rather than a wash fault, and a different page.
Causes, ranked for the DWT build
- The water arriving is not hot enough — It climbs to the top where the machine is a long pipe run from the water heater, because the cycle fills with whatever is in the pipe at that moment. Running the tap hot at the sink before starting is the free version of the test.
- The filter or the sump is loaded with debris — Where there is a filter, this ranks high simply because it is maintenance that nothing reminds you to do.
- The spray arms are blocked, clogged or held by the load — It sits in the middle of the list — common enough to check, cheap enough that finding it early is worth the minute it takes.
- The wash pump, its impeller or the chopper — Last of the five, because everything above it is cheaper and far likelier, and because this is the only one that needs a technician.
The order that finds it fastest
- Spin both spray arms by hand — They should swing freely with the racks in place; hold one up to the light and look for closed jets.
- Lift out the filter and rinse it — Rinse under a tap rather than scraping it.
- Check what temperature the fill actually gets — This is the free test for the temperature cause.
- Look at what is left in the dispenser at the end — A tablet still sitting there names either the cup or the water temperature.
- Reload the racks and run the same load again — Nested bowls and overlapping plates shadow each other, and no machine cleans through another plate.
Before you open anything
Safety
Switch the machine off at its breaker before reaching behind the kick plate or the door panel — water and mains wiring share the same small space in a dishwasher, and a capacitor can hold a charge after the power is off. Leave the door latch and its switch exactly as they are: the machine is meant to stop the moment the door opens.
Where the owner job ends
The condition is whether anything is left that you can reach from inside the tub. Arms, filter, loading, detergent and the temperature of the fill are all in there. The pump, the diverter and the heating circuit are underneath the tub, in a space where mains wiring and water share a housing, and that is a service call rather than an afternoon.
Other faults covered for the DWT models
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
