The short answer first
Start at filter and sump overdue a clean: it is the most common cause on a machine of this kind and the cheapest to correct. Only when the load, the arms and the filter are all right does the machine itself become the suspect.
What this looks like
- A white film or chalky coating on glassware — Water chemistry, detergent or rinse aid rather than a mechanical fault — it wipes off with a little vinegar.
- Dishes on the top rack clean, bottom rack poor, or the other way round — One arm is not doing its job. Which rack fails tells you which arm to look at.
- Dishes come out wet and cold at the end — The final rinse is not reaching temperature, or rinse aid has run out, so water sheets instead of draining off.
- NEAR MISS — the dishes are chipped or etched rather than dirty — Etched glassware is a detergent and water-softness issue, and no repair changes it. Reduce detergent and use rinse aid.
What goes wrong here, in order
- Filter and sump overdue a clean — A blocked filter also restricts flow to the pump, so pressure at the arms falls and coverage drops at the same time. One neglected part therefore produces two different complaints. It comes first for a practical reason: the check takes minutes and it decides which half of this list you need. A value-tier build usually means simpler controls and fewer sensors, which pushes the mechanical causes above the electronic ones here.
- Blocked spray arm jets — Arms are also a bearing: they can stiffen on their spindle or come loose, and an arm that wobbles throws water into the door rather than onto the dishes. Next in order: it explains a smaller share of these faults but is quick to confirm once the first is clean.
- A tall item stopping an arm from turning — Everything in a dishwasher is cleaned by water thrown from spinning arms. A tray laid flat, a pot over the lower arm or bowls nested into each other creates a shadow, and nothing in that shadow gets touched by water at all. Third, and only worth attention once the two above are clean.
- Hard water overwhelming the detergent — Detergent loses strength in storage, particularly once a box or a bag has been open in a damp kitchen for months. The same tablet that worked last year can leave a film this year, and nothing in the machine has changed. It ranks last here: real, but the least common of the four by a clear margin.
Work through it in this order
- Twist the filter out and look at the mesh and the sump beneath it — A mat of debris on the mesh explains a gritty result on its own. Start here — it is free, and it decides which half of the list you are in.
- Spin each arm on its spindle with the racks out — It should turn freely with barely any resistance; anything stiff or wobbling needs attention. Second, and still no tools beyond a torch.
- Load the machine as usual, then spin both spray arms by hand — If either arm stops against something, you have found the fault without opening anything. Third in sequence — useful, but rarely where the answer turns out to be.
The steps, with tools and times
- Wipe the sump and the tub base before the next cycle — Clearing what sits below the filter stops it loading again within a week.
Tools: cloth, gloveAbout 20 min
- Remove the spray arms, clear every jet, and refit them so they spin freely — A cocktail stick clears most jets; do not enlarge them with anything metal.
Tools: cocktail stick, hot waterAbout 25 min
- Run a load at half capacity to test whether results improve — A clean result on a light load is the proof that loading was the problem.
About 20 min
- STOP when the next thing to move is a fixing rather than a cover — Anything held by fasteners is holding something in place for a reason. Write down what you found and leave it there.
The safety part
Safety
Turn the power off at the wall before any panel comes off or a hand goes into the sump. Never tape or defeat the door latch to make the machine run with the door open: that interlock is the only thing that stops a tub of near-boiling water being sprayed into the kitchen.
The line between a fix and a call
Call when the arms are clear, the filter is clean, the load is right and the water is hot, and the results are still poor. At that point the suspects are the wash pump, the heater and the inlet valve, and all three need the machine tested rather than cleaned.
Related Kova Select pages
The limits of this page
Generalized information. It applies across Kova Select dishwashers rather than to one line, and where a more specific page exists it is the better answer for your unit. Not covered here: service-manual procedures, fastener sizes and any figure that changes between families.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
