Say goodbye to doing the dishes.
We've tested compact and standard dishwashers to find out which are the best at washing and drying.
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.
It's hard to work out how old a dishwasher might be. It's also not easy to find out how much water and energy an older model uses.
Several factors affect how well a dishwasher dries dishes:
Our testing also showed dishwashers that scored well in drying were usually not very energy efficient. This is because the drying part of a washing cycle can be the most energy-intensive part of the wash.
A dishwasher’s main job is to wash dishes properly. It’s false economy to choose a model that has excellent water and energy efficiency but can’t do its main job: you’ll just end up using more water and energy rinsing and re-washing dishes.
Drying tends to divide dishwasher users. Some aren't bothered if items come out clean but wet; others want everything bone dry.
Individual scores for washing, drying, water efficiency and energy efficiency vary amongst our recommended models – so when choosing a new dishwasher think about what matters most to you.
Our test results give the total amount of water used by each dishwasher but no longer give a score for water efficiency. This is because water efficiency has improved to a point where almost any dishwasher will use less water than washing the same load by hand. If our tests find a dishwasher that uses an excessive amount of water, we’ll point this out.
Most dishwashers come with a single water connection, and manufacturers usually recommend you hook it up to cold water.
You might be tempted to save money by connecting to your hot water if it comes from a wetback, heat pump or solar unit. But before you do that check the maximum water-inlet temperature (see the test results). Also make sure you have a suitable tempering valve on your hot-water system.
If you have a standard electric hot-water cylinder, allowing your dishwasher to heat its own water will be fractionally cheaper than using the cylinder’s.
Using a cold connection also gives you the full flexibility of all the cycle options on your machine.
Looking after your dishwasher will maximise its life and performance.
All that yucky grease left in your sink and food caught in the plug trap after handwashing dishes goes through your dishwasher. It’s no surprise a build-up of greasy food is enemy number one. Grease and food scraps clog filters and spray arms, strain pumps and reduce the effectiveness of sensors. To keep a dishwasher running efficiently for as long as possible, cleaning is your priority:
Add a capful of rinse aid to a load once a week to keep grease at bay, even if you use tablets with built-in rinse-aid.
Every month, run your dishwasher empty on its hottest cycle with dishwasher cleaner. After the cycle, remove and clean the drain filter with a brush and hot soapy water. Also check behind the door seal, particularly at the bottom, and clean out any grunge.
Every few months, check the spray arms as holes can get clogged. Check your manual to see if you can remove them. If so, clean them along with the filter.
If you get an error code on the control panel, check your manual or turn to Google for an explanation. In many cases, these aren’t terminal — they just indicate the filter is clogged (so water can’t drain) or a sensor is dirty. Before calling for a repair, thoroughly clean the machine and see if that fixes it.
Silver: whether sterling or plated, silver should never go in the dishwasher. Silver tarnishes easily, and once stained polishing may not remove it. It isn’t necessarily the dishwasher that’s at fault, the detergent used can also tarnish silver. We recommend always hand-washing silver.
Fine china: depending on the age and condition of your china, putting it in the dishwasher can wear away at the pattern or chip and break it. It’s also best to leave gold-trimmed crockery out of the dishwasher as the trim can be stripped away.
Crystal and fine glassware: sensitive to temperature and detergents, these types of delicate glassware are prone to cracking and etching. If your crystal has turned cloudy, try cleaning it with a lime remover as it may not be etched. However, once etching occurs, it is irreversible.
Wooden cooking utensils and chopping boards: wooden cookware can warp and crack from repeated washes in the dishwasher. Chopping boards are a bit more resilient, but the wood can end up drying out too much and gaps and cracks can form. After washing, make sure wooden utensils and chopping boards are completely dry before putting them away to prevent bacteria growth.
Utensils with wood or bone handles: the temperatures and detergent in a dishwasher can weaken glue holding the handle to the utensil, causing it to fall off.
Cast-iron cookware: seasoning is the gradual process of building up a protective non-stick surface on cast-iron cookware. Putting a cast-iron skillet in the dishwasher can strip that seasoning and eventually cause it to rust.
Copper pots and pans: while your copper cookware won’t be ruined by putting it in the dishwasher, it can become discoloured and require laborious hand cleaning to restore.
Brass: the hot temperature inside a dishwasher can cause a chemical reaction that eats away at the protective layer on brass. This layer prevents oxidation and tarnishing. Once it’s gone, you’ll need to polish the item to replace it.
Items with labels on them: the dishwasher might seem like an easy way to remove labels from jars. However, once a label peels off it doesn’t go down the drain. It can stick to unseen places in your dishwasher, especially the filter, and cause headaches later on.
Some kitchenware and utensils come with instructions saying to wash in the top rack only. This is because the top rack of a dishwasher is typically cooler during a hot wash than the bottom rack due to the placement of the heating element. Regardless of which rack you use, you should avoid placing any of the items mentioned above in your dishwasher.
It’s tricky to come up with tests for appliances like dishwashers. The items used for a load need to be the same every time, have the same amounts of the same types of food on them, and there needs to be consistency in how many items you load into dishwashers of varying sizes. The problem is you can end up with a load that doesn't look anything like a real family’s.
How dishwasher manufacturers describe capacity doesn’t help either. You might have a 12-place-setting dishwasher, but when was the last time you threw a dinner party for 12 people? Or made dinner but didn't end up with any pots, pans or serving bowls to wash?
Our test uses items that most dishwashers deal with on a daily basis. There’s a steel pot and pan, a large serving dish, mugs, plastic plates, plastic bowls, a large glass bowl and plastic serving utensils. With all of this packed in, there’s only space in most full-sized models for 5 place settings – whatever the manufacturers claim about capacity. Where we used to fit 132 items in a 12-place setting dishwasher, we now have 82.
If a machine has an "auto" cycle, we select it over the "normal" cycle. We do this because an auto or sensing cycle should be designed to give optimum results for every wash. You're also generally paying extra for this feature. If there's no "auto" cycle we test on the "normal" cycle as this is what our members use the most.
We put each dishwasher through its paces at least twice and the scores are averaged.
To really test a dishwasher's ability to clean, we carefully dirty each test load with a range of foods and let them dry for 15 to 18 hours. And we’ve added baked-on porridge to the foods we’ve always used (such as baby cereal, spinach, egg yolk, tomato juice, tea and butter). Each of the foods plays a crucial part in assessing how the dishwasher performs and they’re there to test things like filtration, spray-arm effectiveness, rinsing and automatic sensors.
For water and energy rating labels, dishwashers are tested using a cycle chosen by the manufacturer. Any cycle can be used as long as it's stated in the instruction manual that it's designed to wash a normally soiled load at the machine's rated capacity. This means "economy" cycles can be used by manufacturers to minimise water and energy consumption, and so maximise the number of stars on the rating label.
Economy cycles often dispense with the drying part of the cycle. It saves on power, but means you may have to get out the tea towel.
Our test load also varies from the load used for water and energy rating label tests which doesn’t include items like pots and plastic ware.
The Energy Rating Label has a scale of stars to show how energy efficient a model is, compared to other models the same size/capacity. More stars = more energy efficient.
The energy consumption figure is in kWh and can be used to compare with any other dishwasher. You can use this figure and the kWh cost from your latest power bill to calculate how much this model will cost to run. The average cost of power for a kWh in New Zealand is 25¢. Lower kWh = cheaper to run.
The product’s annual energy consumption in kilowatt-hours (kWh) is based on standards testing. Check the key assumptions used in this testing to make sure they match how you will use the product. Annual energy consumption for dishwashers assumes 365 uses a year. You should only compare star ratings of dishwashers with the same or similar capacities.
For information on energy ratings and how to use them, see our Energy Rating Labels explained article.