How do I clean a dishwasher?

Dishwashers recirculate their water, filtering it between cycles. When that filter clogs, dirty water gets sprayed back onto the dishes — which is exactly the symptom people report as the machine failing. It's a two-minute job that a lot of people don't know exists.

What you'll need

• Dishwasher cleaner or white vinegar
• Old toothbrush
• Cocktail stick or wire
• Cloths

Step by step

1. Remove the bottom rack and take out the filter assembly.Usually a cylinder that twists out, plus a flat mesh underneath. Check the manual if it isn't obvious.
2. Rinse the filter under hot water and brush it clean.Expect food debris and grease. This is the single most impactful step.
3. Check the sump underneath for debris — glass fragments, labels, bones.Things that get past the filter collect here and can damage the pump.
4. Take out the spray arms and check every hole is clear.A cocktail stick clears blocked holes. Blocked arms mean whole areas of the machine get no water.
5. Wipe the door seal and the bottom edge of the door.Grease and residue collect here and it's the usual source of dishwasher smell.
6. Run an empty hot cycle with a dishwasher cleaner or a cup of white vinegar in a bowl on the top rack.This clears the internal pipework and limescale.
7. Check and top up the salt and rinse aid if your machine uses them.In hard water areas, salt is what prevents limescale damage — running out affects both cleaning and machine life.
8. Clean the filter monthly and run a cleaning cycle quarterly.Both are quick and both prevent the gradual decline people mistake for the machine wearing out.

Tips

• Scrape plates but don't pre-rinse them thoroughly. Modern detergents need some soil to work against, and many machines have sensors that adjust the cycle based on how dirty the water is.
• If glasses come out cloudy, it's either limescale (check the salt) or etching from very soft water plus too much detergent. The two look similar and need opposite fixes.
• Don't overload, and make sure nothing blocks the spray arms from rotating — check by spinning them by hand before starting.
• Leaving the door ajar after a cycle lets it dry out and prevents most smells.

Common mistakes

• Never cleaning the filter — The most common cause of poor cleaning results and bad smells.
• Blocking the spray arms with tall items — Whole sections of the load get no water at all.
• Ignoring the salt indicator in a hard water area — Limescale builds up internally and shortens the machine's life.
• Pre-rinsing everything thoroughly — Wastes water and can make the detergent less effective.

Questions people ask