Seven things you need to know before buying a dishwasher this Black Friday

Looking for a new dishwasher deal this Black Friday? 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 Black Friday adverts.

For more shopping advice and expert tips, see our guide to Black Friday 2023 

1. How efficient is it?

The table shows the average star rating for the energy efficiency of the main program for dishwashers we've tested since 2019. 

It shows that dishwashers have become a little more efficient with energy over the past few years. 

The energy use of dishwashers still varies wildly, ranging from a mediocre three stars to the full five stars for efficient dishwashers. 

Based on dishwashers we had online in February 2024, running costs range from an affordable just under £50 per year to a budget-busting £96.30. 

The Bosch SMS4HMI00G (£669) and Samsung DW60M5050BB (£429) are both full-sized dishwashers from big brands. Yet, while using the main program (with our testing load) five times a week, the Bosch would cost you £56.44 a year to run, while the Samsung would set you back £83.38. 

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:

1. 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.
2. 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.
3. Two-stage – two consecutive washes in one program for an extra-intense clean. Handy for very soiled dishes, such as a greasy baking tray after cooking a roast.
4. Two-zone – 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.
5. Delicates – another gentle wash setting, usually at 45°C, designed to go easy on fine china, glassware and crockery.  

Read our glossary of dishwasher programs to find out more

3. Is it wasting water?

The average water-efficiency rating has gone up from 4.2 to 4.4 stars (out of five) in the past three years. This shows that, on average, dishwashers sold today use a little less water than older models.

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, fruitbowl, 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