How does a dishwasher work?

No bath of water, just 3 litres sprayed round and round by arms that spin on their own recoil. A dishwasher lets in only about 3 litres at a time. No motor turns the spray arms. The holes are drilled at a slant, so each jet pushes the arm the other way, like a lawn sprinkler.

Read how it works: How does a dishwasher work? · The history of the dishwasher · More boxes on Glassbox

Chapters in this interactive model

1. Inside a dishwasher: A steel box, two spinning arms, a pump, a heater and a few litres of very busy water.
2. Why the spray arms spin: No motor turns them. Every tilted jet pushes the arm the other way.
3. One wash, stage by stage: Rinse, wash hot, rinse, rinse hotter, dry: the same few litres, used again and again.
4. How the dishes get clean: Soap from fat, enzymes that snip food apart, a salt swap, and water that forgets to bead.
5. Why dishes dry, and plastic stays wet: The heat stored in hot dishes does the drying. Plastic stores too little.
6. Machine or sink: which uses less?: A full dishwasher uses about 10 litres. Washing the same by hand often takes ten times more.