Appliances
Dishwasher leaving grit and grease? Fix the basics
A dishwasher does not spray fresh water all cycle. It recycles the same few litres, over and over, through a filter you have possibly never met. When plates come out gritty or glasses greasy, that filter, the spray arms and the salt reservoir are the suspects, in that order.
By the Tickover team · Published 30 January 2026 · 5 min read
How the machine actually washes
The machine fills once, heats the water, and a pump fires it through the spinning spray arms again and again. The filter in the floor catches food so it is not sprayed back over your crockery. A clogged filter or blocked arm jets means every plate gets showered in yesterday’s dinner, finely milled.
That is why grit is good news, in a way: it points at maintenance, not a broken machine. Grease is the same story with a different cause, usually water that never got hot or detergent that never dissolved.
The ten-minute reset
Filter, arms, seal, refill
Switch it off and slide the racks out
Turn the machine off at the plug or its fused switch before your hands go in. Bottom rack out fully so you can reach the floor of the tub.
Twist out the filter assembly
The cylinder in the floor unlocks with a quarter turn. Rinse the mesh under a hot tap with a soft brush until water runs through freely.
Unclip the spray arms
Most lift or unscrew without tools. Hold each one up to the light: the jets should be clear pinholes, not crusted craters.
Toothpick every blocked jet
Push debris out of the holes, then flush the arm through at the tap. Limescale, seeds and glass slivers are the usual squatters.
Wipe the door seal and its lower lip
The strip under the door catches a shelf of grime the spray never reaches. Hot soapy cloth, nothing sharper.
Refill salt and rinse aid, then run hot
Top both up, refit everything, and run the hottest empty cycle with a dishwasher cleaner to strip grease from the parts you cannot see.
Salt and rinse aid are not optional
Much of Britain sits on hard water, and dishwashers carry their own water softener: a resin bed that only works if the salt reservoir feeds it. Run it empty and limescale films the heater, the jets and every glass in the house. Rinse aid does the other half, breaking surface tension so water sheets off instead of drying into spots.
All-in-one tablets claim to cover both. In soft water they largely do; in hard water they need the salt and rinse aid topped up regardless. The dishwasher’s warning lights are not decorative, and the streaky glasses arrive within weeks of ignoring them.
Loading is physics, not tidiness
Load for the spray, not the eye
Do
- Scrape plates; enzymes in the detergent need food to work on
- Face the dirty side toward the spray arms
- Big items at the sides and back, never flat over the base
- Point knives down and mix cutlery so it cannot nest
Don’t
- Do not pre-rinse everything to spotless; scrape and load
- Do not let tall trays block a spray arm mid-spin
- Do not stack bowls inside each other
- Do not park anything against the detergent door
Keep it cleaning
- Filter rinsed weekly, deep-cleaned monthly
- Spray arm jets checked monthly
- Salt topped up when the light says so
- Rinse aid dosed up and dial checked
- Hot empty cycle with cleaner monthly
- Door seal and lower lip wiped
When it is a real fault
If the basics are done and the machine still washes cold, with tablets half-dissolved in the tray and grease everywhere, the heating element or its sensor has likely failed. Cutlery still wet and cold at the end of a cycle is the same clue. That is an engineer repair behind the casing, not a DIY one, and the honest maths lives in the repair or replace guide.
If the element has gone
Element repair, fitted
The element itself
the part an engineer fits
Typical UK ranges, mid-2026, as a guide only. Your home, your area and the job itself all move the number — always compare real quotes.
Water pooling in the base after a cycle points the other way, at the drain path: filter, drain hose, then the spigot where it joins the sink waste. The machine shares that plumbing with the sink, and shares its blockages too.
Still washing badly?
Self-Diagnose in the Tickover app runs your dishwasher’s symptoms through a few questions and tells you the likely cause, whether it can wait, and what a repair engineer will want to know.
And if the machine is spotless but the kitchen smells, the culprit is usually its neighbour: the washing machine runs on the same cool-wash habits and grows the same biofilm.
Quick answers
Why is my dishwasher leaving grit on glasses?
Grit means food particles are being recirculated instead of caught, which points at a clogged filter or blocked spray arm jets. Twist out the floor filter and rinse it, clear each jet with a toothpick, and run a hot empty cycle with a dishwasher cleaner. If grit persists, check the salt level: limescale roughens glass too.
Do I still need salt and rinse aid with all-in-one tablets?
In hard water areas, yes. Tablets carry small amounts of both, but not enough to regenerate the built-in softener or sheet water off glassware where limescale is heavy. Keep the salt and rinse aid reservoirs topped up and let the machine’s own sensors decide how much to use. In truly soft water areas you can rely on tablets alone.
Should I rinse plates before loading the dishwasher?
Scrape, do not rinse. Modern detergents use enzymes that attach to food residue; on pre-rinsed plates they have nothing to grip and can etch glassware instead. Scraping solids into the bin and loading the rest saves water and washes better. The one exception is anything left to fossilise overnight, which deserves a soak.
Is a dishwasher heating element worth repairing?
Usually, if the machine is mid-life. An element repair typically costs £90 to £180 fitted, with the part itself £20 to £60, against £250 or more for a decent new machine. Dishwashers commonly serve 9 to 12 years, so a five-year-old machine justifies the fix and a twelve-year-old one rarely does.
This guide is general information for UK homes, not advice about your specific property. Anything involving gas must be done by a Gas Safe registered engineer, and notifiable electrical work by a qualified electrician. If you smell gas, call the National Gas Emergency line on 0800 111 999. If you’re ever unsure, stop and get a professional in — that’s exactly what Tickover is for.
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