Denys Mitchell Key Takeaways
- Every modern Asko catches food waste in a removable filter rather than grinding it away.
- Standing water at the end of a cycle is the first sign, and it is usually misread as a failed pump.
- The filter cylinder must be turned until it locks — a loose one lets waste straight into the pump.
- Silted spray arm holes are why one rack comes out clean and the other does not.
- Do not pre-rinse dishes spotless: the detergent enzymes need something to work on.
The Bottom Line
Rinse the filter monthly and wash the coarse screen quarterly. If water still stands in the tub with both clean, the fault is in the pump or the drain path and needs a technician.
Asko dishwasher filter maintenance is the difference between a machine that runs for twenty years and one that starts throwing drain faults at year six. Modern dishwashers catch food waste in a filter instead of grinding it away, and that filter has to be taken out and rinsed. Nobody is told this at delivery, and it is behind most of the drain complaints on this site.
| Task | How often | What it prevents |
|---|---|---|
| Rinse the filter assembly | Monthly | Drain faults, odor, grit on dishes |
| Wash the coarse screen | Every 3 months | Standing water |
| Clear the spray arm holes | Every 3 months | One rack coming out dirty |
| Check the drain hose loop | Once a year | Backflow from the sink |
| Run a hot maintenance cycle | Every 3 months | Grease film, scale |
Where the Filter Is and How It Comes Out
Open the door, pull the lower basket right out, and look at the floor of the tub. There is a filter assembly in the middle or toward the back: a fine cylindrical part seated inside a flatter coarse screen.
- Turn the cylinder counterclockwise and lift it straight out.
- Lift the coarse screen away underneath it.
- Rinse both under a tap, with a soft brush on the mesh if greasy.
- Refit the screen first, then the cylinder, and turn until it locks.
The lock is not optional. A cylinder sitting loose lets waste straight through to the pump, which is exactly the failure the filter exists to prevent.
What a Neglected Filter Looks Like From Outside
- Water standing in the tub at the end of a cycle. The first sign, and the one people misread as a failed pump.
- Grit on clean dishes. The machine is recirculating what it caught last time.
- A smell that returns a day after cleaning the tub. The smell lives in the filter, not the tub.
- Cycles running noticeably longer. The control extends them when it cannot reach the water quality it expects.
If a drain code appears alongside these, clean the filter before looking anything up — on this class of fault the code often clears by itself once water can move.
The Spray Arms Are the Other Half
The filter catches debris; the spray arms distribute water. When the small holes silt up with scale or trapped food, one rack stops getting washed properly while the other looks fine.
Both arms unclip without tools on most Asko models. Hold each up to the light and look through the holes; a toothpick clears them. Five minutes fixes a complaint most owners treat as the machine wearing out.
Scrape, Do Not Pre-Rinse
Modern detergent contains enzymes that need something to work on. A load rinsed spotless before it goes in gives them nothing, and results get worse rather than better. Scrape the plates, leave the rest, and let the machine do its job — the filter is there precisely so you can.
What This Will Not Fix
A dishwasher that fills but never drains with a clean filter has a pump, a check valve, or a blocked disposal knockout — the last being the classic after a new disposal is fitted. A machine that will not start at all is a door latch or a control problem. Neither is maintenance, and our guide on what those repairs cost covers where they go.
When to Call
If the filter is clean, the spray arms are clear and water still stands in the tub, stop cleaning and have it looked at. Our Asko dishwasher repair service covers the drain path and the control side, and preventive maintenance exists for owners who would rather have it done on a schedule.
Diagnostic work starts from $89, with the final price confirmed after the on-site diagnosis and a written estimate before any work begins. Book a visit once the easy causes are genuinely ruled out.