- Size: A lot of 12- to 15-place models fit roughly the same-sized under bench space (82-85cm height, 60cm width and 55cm to 65cm depth). If you are replacing an existing dishwasher, check the fit before you order. Some models come with a worktop that must be removed before building in. Check the ventilation space requirements. If you’re looking for a dishwasher to squeeze into a small space, a compact or slimline model might be right for you.
- Capacity: The dishwashers in our test database come in sizes up to 15 place settings. Overfilling a dishwasher with extra crockery and cutlery reduces wash performance.
Adjustable top basket: Essential if you want to wash champagne flutes or other tall wine glasses, or wash very large plates in the lower basket. Some models let you lower one side of the basket, so you can wash tall glasses and large plates at the same time.
Removable or folding tines allow large or awkwardly shaped objects to fit in the baskets. Watch out for short tines – plates can fall over onto each other and prevent a good wash.
Take along a few pieces of your everyday dinnerware such as a large plate, a deep bowl and a long-stemmed glass. See how they fit – check that the baskets can close and the spray arms can spin without hitting anything.
Anti-nesting grids: Fitted over the cutlery basket to prevent cutlery bunching together. Removable grids are more versatile and easier to use.
Cutlery tray: Here's an innovation in some models you'll either love or hate. Critics find it time consuming and fiddly to load, because each piece of cutlery has to go in its own slot – the right way round. And it can prevent tall glasses from fitting, unless the tray is removed.
Our test found there was no performance advantage with a cutlery tray. A basket may be offered as an alternative or in addition to a tray.
- Program options and features: What do you want your dishwasher to do? The options vary. A low temperature wash saves power, and lets you take advantage of the new enzyme detergents. A delicate cycle is useful for fragile items. A fast-wash function is efficient if you've pre-rinsed the plates to remove the worst of the grime. A half-load option reduces the amount of detergent, power and water required.
- Cycle time: A normal cycle takes around 2 to 2.5 hours. Some models have a fast cycle, and those with a hot connection will be quicker than those which heat the water themselves.
- Auto-sensing: Where a dishwasher has an auto-sensing cycle we use that for testing. An auto-sensing cycle adjusts wash time, temperature and energy level to suit the amount of dirt in the wash water. But our tests have found some auto-sensing machines aren't always consistent in their choices.
- Displays: It's helpful to see how soon the cycle will finish, or where to look to fix simple problems, such as blocked spray arms.