The short answer
A Bertazzoni DW dishwasher that leaves dishes dirty is usually failing to deliver water where it needs to go, not failing to heat it. On this family the spray arms, the filter and the loading pattern account for most of it, and the wash pump and heater sit well below them in the order.
What an owner actually sees
- Gritty particles redeposited over everything — The filter is loaded and the machine is recirculating its own debris. This is the single most common presentation on this appliance.
- One rack clean, the other not — A spray-coverage split. Either that arm is not turning, its jets are blocked, or something in the load is fouling it.
- A white chalky film on glassware — Hard water and detergent chemistry rather than a mechanical fault. It responds to rinse aid and dosing, not to parts.
- NEAR MISS — the machine is also not draining — Standing water at the end of a cycle is a drainage fault, and dirty dishes are only its side effect.
What it usually turns out to be, in order
- Filter loaded or seated incorrectly — First on this family, and first because owners are frequently unaware the filter needs periodic cleaning at all. Once it is loaded the machine washes with suspended debris and redeposits it, which produces exactly the gritty finish people describe.
- Spray arm jets blocked, or an arm not turning — Second. Hard-water scale and food fragments close the small jets first, so coverage degrades gradually and the owner blames the detergent.
- Loading pattern blocking coverage — Third, and free to rule out. Tall items, oversized trays and pan handles reaching down through the upper rack all stop an arm dead.
- Water temperature or detergent dosing wrong for the water — Fourth. Detergent that never dissolves cannot clean, and hard water binds it before it works. This produces film and poor results without any part having failed.
Check in this order, and why
- 1. Pull and clean the filter assembly — Remove it, rinse it, check it seats fully on refitting. On this family this is the first step and it closes a large share of these calls by itself. The DW family covers several builds, so confirm which one you have in the table below before committing to any teardown.
- 2. Spin both spray arms by hand and hold each jet up to the light — Any arm that catches, and any jet you cannot see through, is your coverage fault. Clear jets with a wooden pick rather than wire. With several models in the family, note yours from the table before quoting a part number to anyone.
- 3. Load the machine as the household actually loads it, then spin the arms again — This is the step that catches the tall item nobody thought about, and it is the difference between a real diagnosis and a parts guess. Leave this until the cheaper checks are settled.
Read this before touching the appliance
Safety
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. Opening the door mid-cycle releases steam and hot water, so open it a crack, stand aside and let the machine stop before looking in.
Models in the DW family — The model numbers this page covers.
Reference| Model number | Family key |
|---|---|
| DW11UBT32D129 | bertazzoni:dishwasher:dw |
| DW18PR | bertazzoni:dishwasher:dw |
| DW18S2IPV | bertazzoni:dishwasher:dw |
| DW18S2IXV | bertazzoni:dishwasher:dw |
| DW24PR | bertazzoni:dishwasher:dw |
| DW24S2IPB | bertazzoni:dishwasher:dw |
| DW24S3IPV | bertazzoni:dishwasher:dw |
| DW24T2IPB | bertazzoni:dishwasher:dw |
| DW24T2IXB | bertazzoni:dishwasher:dw |
| DW24T31PT/26 | bertazzoni:dishwasher:dw |
| DW24T31XT/26 | bertazzoni:dishwasher:dw |
| DW24T3IPT | bertazzoni:dishwasher:dw |
| DW24T3IPT/26 | bertazzoni:dishwasher:dw |
| DW24T3IPV | bertazzoni:dishwasher:dw |
| DW24T3IXT | bertazzoni:dishwasher:dw |
| DW24T3IXT/26 | bertazzoni:dishwasher:dw |
| DW24T3IXV | bertazzoni:dishwasher:dw |
| DW24XT | bertazzoni:dishwasher:dw |
| DW24XV | bertazzoni:dishwasher:dw |
| DW60BI/24 | bertazzoni:dishwasher:dw |
Owner fix or service call
Call when the filter is clean, both arms turn freely with clear jets, the load is not obstructing anything and the results are still poor across both racks, because that pattern points at wash pressure and that means the pump or the diverter. Call as well if the machine sounds different during the wash — a pump that has lost prime or picked up debris changes its note. Filter cleaning, jet clearing and loading corrections are all owner work and resolve most of these calls without a part.
Nearby pages for these models
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