Dishwasher Not Washing Properly
If your dishwasher is not washing properly, dishes are coming out dirty, greasy or with food still stuck to them after a full cycle. This is a common complaint and in most cases it can be resolved with some straightforward checks and maintenance before calling an engineer.
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Select your dishwasher brand below for a specific guide including the relevant error codes for your appliance.
Why Is My Dishwasher Not Washing Properly?
When a dishwasher leaves dishes dirty after a full cycle, the cause is usually a maintenance issue rather than a mechanical fault. The most effective first steps are cleaning the filter, checking the spray arms and ensuring salt and rinse aid levels are correct.
Common Causes
Blocked dishwasher filter
The most common cause. A clogged filter prevents water from circulating properly and reduces wash performance significantly. The filter should be removed and cleaned at least once a month.
Blocked spray arms
The spray arms distribute water around the dishwasher during the cycle. If the holes in the spray arms are blocked with limescale or food debris, water cannot reach all areas of the tub and items will come out dirty.
Low or empty salt reservoir
Dishwasher salt softens the water and prevents limescale build-up. If the salt reservoir is empty, wash performance will deteriorate, particularly in hard water areas.
Low or empty rinse aid reservoir
Rinse aid helps water drain off dishes cleanly and prevents spotting. Without it, dishes may come out dirty and streaky.
Overloaded or incorrectly loaded dishwasher
If items are stacked too closely together or placed incorrectly, water cannot reach all surfaces. Larger items should not block the spray arms from rotating freely.
Wrong programme or temperature selected
A short or eco programme may not provide enough water temperature or cycle time for heavily soiled loads. Use a more intensive programme for pots, pans and heavily soiled items.
Insufficient or wrong detergent
Using too little detergent, or a detergent that is not suitable for use in an automatic dishwasher, will result in poor cleaning performance.
Checks To Try Before Calling An Engineer
Clean the filter
Remove the filter assembly from the bottom of the tub, rinse thoroughly under running water and refit securely.
Clean the spray arms
Remove the spray arms — they usually unclip or unscrew — and rinse them under running water. Use a toothpick or thin wire to clear any blocked holes. Refit securely before running the next cycle.
Check salt and rinse aid levels
Top up the salt reservoir and rinse aid dispenser if low. The indicators on the control panel will tell you when these need refilling.
Run a hot maintenance wash
Run an empty cycle on the hottest programme with a dishwasher cleaner tablet or a cup of white vinegar in the bottom of the tub to remove grease and limescale build-up.
Check the loading
Reload the dishwasher ensuring items are not blocking the spray arms and that water can reach all surfaces.
When To Contact A Professional
If wash performance remains poor after the above checks, there may be a fault with the water inlet valve, heating element or circulation pump that requires professional diagnosis. Internal components should only be inspected or repaired by trained professionals.
Related Dishwasher Fault Guides
Dishwasher Leaving White Residue On Dishes
Dishwasher Not Filling With Water
Related Guides
Dishwasher error codes — all brands
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