Dishes coming out dirty, gritty or cloudy
Three quite different problems get described the same way. Working out which one you have takes one look at a glass and saves you buying the wrong thing.
What it usually means
"It is not cleaning properly" covers three separate faults with three separate fixes, and the symptoms are distinguishable if you know what to look at.
Food still stuck on the dishes means water is not reaching them with enough force. That is a circulation problem: blocked spray arm jets, a filter so clogged the pump cannot draw through it, or arms that cannot spin because a baking tray is fouling them.
A white, gritty film on everything, including the inside of the machine, is limescale. That is a water hardness problem, and in most of England it is a question of when rather than whether. It is what the salt reservoir and the built-in water softener exist to prevent.
Permanently cloudy glasses that do not improve when you rub them are usually etching, which is different again and worth knowing about because it is irreversible. Etching is caused by glass being attacked by detergent that is too aggressive for very soft water, or by running very hot cycles with delicate glassware. No amount of rinse aid brings an etched glass back.
The test that separates limescale from etching takes ten seconds. Dip the glass in white vinegar. If the cloudiness lifts, it was limescale and you have a treatable problem. If it does not change, the glass is etched and the damage is permanent — though correcting your detergent dose and water hardness setting will stop it happening to the rest.
How to narrow it down
Work through these in order.
Does the cloudiness come off with vinegar?
Yes means limescale — check your salt, your rinse aid and the machine’s water hardness setting. No means etching, which cannot be reversed, but can be stopped from spreading to the rest of your glassware.
Can you spin the spray arms by hand?
Open the door and turn each arm through a full circle. If anything catches — a tray handle, a tall utensil, a plate poking through the basket — it was not spinning during the cycle and that alone explains dirty dishes.
Are the little holes in the spray arms clear?
Hold an arm up to the light. Blocked jets are usually limescale or seeds, and most arms unclip for cleaning. A cocktail stick clears the holes without enlarging them; a drill bit does not, so do not.
When did you last top up the salt?
If you have never added any and you are in a hard water area, the softener has been doing nothing for years. Use dishwasher salt specifically — table salt and cooking salt contain additives that damage the softener unit, and that is a repair rather than a top-up.
Is the water actually getting hot?
Open the door partway through a hot cycle. If the interior is barely warm and there is no steam, the heating element may have failed, and no dishwasher cleans in cold water regardless of what else you fix.
When it is urgent
Take care
What it costs
Typical repair cost
£0–£220
Typical UK prices including parts and labour, updated August 2026. Your quote may differ.
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