What do dishwasher programmes actually do?

Dishwasher programme names are marketing, but underneath them the machine only has three levers: how hot the main wash gets, how long it holds that temperature, and how many fills of water it uses. Every named programme is a preset combination of those three. Once you can see which lever a programme pulls, the names stop mattering.

Step by step

1. Understand the trade-off eco actually makes.Eco heats to around 50°C instead of 60-65°C and compensates with time — often three to four hours. Detergent enzymes work slowly at lower temperatures, so the result is the same but the energy used to heat water is much lower. Longer does not mean harder on the dishes.
2. Use auto or sensor programmes for genuinely mixed loads.A turbidity sensor measures how dirty the water is after the first fill and extends or shortens the cycle accordingly. It is the best default when you never know how dirty a load is, and it will happily run long when the load deserves it.
3. Reserve the intensive or pots programme for baked-on food.It runs the main wash at 65-70°C with a longer pre-wash and more water changes. It is the right answer for roasting tins and casserole dishes, and it is hard on anything with a coating or a glaze.
4. Treat the quick or one-hour programme as a rinse-and-refresh, not a wash.It shortens the main wash and usually cuts the drying phase entirely. It handles crockery used for a light meal an hour ago. It does not handle egg, cheese, porridge or anything that has dried on.
5. Know what the glass or delicate programme changes.A lower temperature, typically 40-45°C, and a gentler spray pressure to reduce thermal shock and clatter. It protects decorated and thin glass, but it will not clean heavily soiled items.
6. Use the pre-rinse or soak programme instead of rinsing at the sink.A cold water rinse with no detergent and no heating, for a part-filled machine you will not run until tomorrow. It uses a few litres and stops food drying on, which is far less water than rinsing plates under a running tap.
7. Read the extras as modifiers rather than programmes.Extra dry adds heat or time to the drying phase. Hygiene or extra hot raises the final rinse to about 70°C. Half load reduces water and time. Zone wash concentrates pressure on the lower basket. Each one alters the base programme rather than replacing it.
8. Set delay start against your tariff rather than against your bedtime.Every machine has one. If you are on a time-of-use tariff, this is the single control that saves you real money, and it costs nothing to use.

Tips

• The temperature on the display is the main wash temperature, not the final rinse. The final rinse is usually hotter, and it is the one that does the sanitising and drives the drying.
• If the machine is left on the eco programme permanently and results start slipping, run one intensive cycle a month. The higher temperature clears grease from the pipework that a cooler cycle leaves behind.
• A cycle that keeps running much longer than its stated time is not faulty. Sensor programmes extend, and cold incoming water in winter adds heating time to every programme.

Common mistakes

• Using the quick programme as the everyday default — It skips the soak and shortens the main wash, so food residue survives and gradually accumulates in the filter and the pipework. Machines run on quick cycles are the ones that start to smell.
• Avoiding eco because a three-hour cycle sounds wasteful — Time is nearly free; heating water is not. The long cycle exists precisely because it uses less energy, and eco is usually the cheapest programme on the machine by a wide margin.

Questions people ask