7 things you need to know before buying a dishwasher

Looking for a new dishwasher? You might think they haven't changed much since you last bought one, but there are plenty of new features and things to consider.

Dishwashers today are smarter, more feature-packed, bigger and (slightly) more efficient than they used to be.

Here's what to consider before you buy, so you don't get swayed by flashy promises on adverts.

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1. How efficient is it?

Dishwashers have become more energy efficient in recent years, but the energy use of machines still varies wildly - ranging from a mediocre three stars to the full five stars for efficient dishwashers. 

Based on the 184 dishwasher reviews we currently have online, running costs of a full-sized dishwasher range from just under £48 per year to a budget-busting £98. 

The Bosch SMS4HMI00G and Samsung DW60M5050BB (both around £500) are full-sized dishwashers from big brands. Yet, while using the main program five times a week, the Bosch would cost you £57.27 a year to run, while the Samsung would set you back £84.60. 

So it's always worth checking our dishwasher reviews before you buy to get an idea of how cheap a machine will be to run. 

Find out which are the most energy efficient dishwashers

2. Do I need the fancy programs?

Most dishwashers have a main (often called 'auto') program, along with settings for eco and quick wash. 

However, many new dishwashers have even more programs, including:

• Intensive – A usually 70°C hot and intensive wash designed for very soiled dishes, such as a greasy baking tray after cooking a roast.
• Delicates – a gentle wash setting, usually at 45°C, designed to go easy on fine china, glassware and crockery.  
• Multi-zone – This runs a gentle wash of the top rack (usually for glasses), combined with a more intense wash on the bottom rack for pans and tough grime.
• Silent or quiet – increasingly common in premium dishwashers, these programs are claimed to reduce the noises made during the filling and washing cycles, which is handy if you live in an open-plan home
• Steam, hygiene or baby protect – an intensive wash combined with a rinse that includes a burst of higher temperature up to 70°C. Or sometimes it's a higher-temperature short-burst rinse finishing off a normal program. These programs are often promoted as leaving dishes germ-free.

Read our guide to dishwasher programs to find out more

3. Is it wasting water?

Based on previous data analysis, modern dishwashers have become more efficient at using water during wash cycles, especially when compared to washing up by hand.   

A typical washing-up bowl holds 9 litres of water. We estimate that you can wash around two place settings* with one washing-up bowl before needing to refill it. 

A full-sized dishwasher can wash and rinse between 12 and 16 place settings using the same amount of water, so it's by far a more efficient way to wash your dishes.

To get the same water efficiency from washing up by hand, you'd need to clean at least a dozen plates, bowls, cups, mugs and lots of cutlery in a single washing-up bowl.

How much water does it take to wash two place settings?

*The Association of Home Appliance Manufacturers (AHAM) defines the following as one place setting: a cup, saucer, dinner plate, side plate, fruit bowl, glass, dinner fork, salad fork, knife and two teaspoons.

To find out more, read Which? research reveals how little water dishwashers use compared to hand washing

4. Built-in dishwasher or not?

Built-in or integrated dishwashers are designed to blend in with your kitchen, hidden behind a cabinet door.

This is great if you want your kitchen to look streamlined, but they're often more expensive than freestanding models.

The controls and display aren't usually visible at a glance, either, so you can't take a quick look to see if your wash is almost finished. 

However, some modern dishwashers, such as the Bosch SMV6ZCX01G, get around this by projecting the time remaining straight on to the floor in front.

5. How many place settings do I need?

Dishwasher capacity is getting bigger. Around 10 years ago, the biggest you could find held 14 place settings, but now you can find many that fit 16 place settings.

This doesn't necessarily make loading and unloading them any easier, though. In fact, our testing shows that to fill a 16-place setting dishwasher to maximum capacity, you have to really squeeze everything in. 

For those who don't need so much space, there are still plenty of regular dishwashers that hold 12 or 13 place settings.

A slimline dishwasher might also be worth considering if you don't have much space, or don't generate as much washing up. Slimline models typically have around seven to nine place settings. 

We've sometimes found slimlines trickier to load, and our lab tests reveal that they are, on average, less energy and water efficient than full-sized dishwashers.  

6. Should I go smart or not?

Smart dishwashers connect to your home wi-fi network and pair with an app on your smartphone or tablet.

They started out pricier – usually more than £600 – but recently we've seen models available for less than £300.

Most allow you to start your dishwasher from your phone, but some can also automatically order more detergent on a timer and download new programs. They can also let you monitor energy consumption and get troubleshooting diagnostics.

This should give you greater flexibility to operate your dishwasher, but it's not a necessity.

If you forget to put your dishwasher on, being able to do it from your smartphone won't be much use – there won't be any detergent in there (unless your dishwasher has an auto-dosing feature). Plus, there are safety aspects to consider with running electrical appliances when you're not at home.

See all our smart dishwasher reviews

7. Does it come in a different colour?

Black, silver, stainless steel, cream and even bright red dishwashers are available nowadays, but you could have to pay a premium to get the same dishwasher in something other than white.

If you want a different colour it will limit your choice, as many retailers only sell one colour – usually white or black.

Dishwashers with a stainless-steel exterior will cost more as stainless steel is more expensive than the plastic many dishwashers are made from.

Compare our reviews of black dishwashers, silver dishwashers and stainless steel dishwashers. Or just focus on the best dishwashers