Washer-dryer features explained

Below, we explain the key features to consider when choosing a washer-dryer, from drum size to spin speeds and 'fuzzy logic' sensors. 

We also run through a number of useful wash programs that you may like to look out for choosing a new appliance.

Ready to buy? Check out the best washer-dryers according to our rigorous tests

Washer-dryer features

Washing programs

All washer-dryers offer a suite of standard washing programs, which includes settings for cottons, man-made materials and delicate fabrics at a range of different temperatures.

Most models have additional options, such as pre-wash, spin and extra rinse, and some have special cycles designed for specific scenarios, such as hand-wash, curtains, sportswear, trainers and more.

Scroll down for more on useful washer-dryer programs.

Drum size/capacity

Washer-dryers are all of a very similar size on the outside, but their washing capacities vary between 4.5kg and 12kg of laundry, and they can dry 2.25kg to 7kg (don't forget that the washing capacity will always be higher than the drying capacity). An extra kilogram equals around five T-shirts or one large sheet. 

Bigger isn't necessarily better when it comes to capacity. If you don't fill up the drum, the larger washer-dryers can be less efficient, because they use so much water in each wash. If you wash or dry with a full load in a larger machine, you use less energy, water and time per item.

For further advice, read our guide to washer-dryer size, capacity and spin speed

Extra rinsing

Many washer-dryers are poor at rinsing, so the ability to add an extra rinse can sometimes ensure more detergent is removed from laundry. This is useful for people with eczema, sensitive skin or allergies.

If you have a problem with undissolved detergents, consider switching to liquid detergents, particularly for quick-wash programs.

Variable spin speed

This lets you vary the spin speed of the machine to protect woollens, handwash-only clothes and delicate items from damage.

It's useful if the default spin speed for your machine is higher than 1,000rpm, which can be too quick for some garments. 

Delayed start

This allows you to set the washer-dryer to automatically start in a few hours time, which is useful if you want the machine to work while you are out of the house, or overnight. Some washer-dryers with this feature let you set the machine up to 24 hours in advice, while others only allow smaller delays.

We do recommend to only run your laundry appliances when you're at home and awake though, for fire safety reasons.

Smart capabilities

Not only does that mean you can start and stop your wash from the comfort of your sofa, some models also allows you to track your energy usage and troubleshoot any potential issues. There are usually some extra programs on the mobile app too.

Filter

All washer-dryers have a filter, which catches fluff whipped up when drying, as well as bits of debris. They need to be cleaned regularly, which can be a pain on some models because they are often close to the ground and can be fiddly to open.

Condenser

The condenser in a washer-dryer cools moist, hot air inside the machine, producing water which pours down the drain. This process uses a lot of water itself, making some washer-dryers a poor choice for people with a water meter.

However, one benefit of a washer dryer over a condenser tumble dryer (or a heat-pump model) is that you won’t have to remove and empty a waste-water tank when it’s full. Water from the drying clothes is drained away, rather than collected in a tank – this is helpful as water tanks can be heavy and unwieldy when full, so there’s one less chore to do.

Energy ratings

Washer-dryers are rated between A+ and G for energy efficiency, with A+ being the most efficient. Although the ratings officially go down to G, in practice you won't see new machines below C in the shops.

We assess the energy and water use of every washer-dryer we test in the Which? test lab, and give each one a star rating for energy efficiency, as well as an estimate of how much each will cost to run.

To compare washer-dryers for energy use and running costs, go to our washer-dryer reviews, or just skip straight to the best energy-efficient washer-dryers 

Useful washer-dryer programs

Quick-wash program

Most machines have a quick cycle of 50 to 70 minutes (standard washes are usually nearer two hours) which work best for clothes that aren't too dirty. In most cases, though, quick-wash programs can come with a reduced wash capacity.

Woollens program

This is a gentler program for cleaning wool-mixture clothes, which can become bobbly on normal programs.

Only items marked as 'pure new wool' and 'washable', 'pre-shrunk' or 'non-matting' should be washed using the wool program – check the label on your item if you're unsure. 

You should wash all other types of wool with a handwash program or by hand.

Reduced-ironing program

We've found that there can be little difference between a load washed and dried on an easy-iron program and one washed on a standard cycle.

Using lower spin speeds can help to reduce creases though, if you're looking to spend less time behind the ironing board.

Handwash program

This is intended for garments made of delicate materials such as cashmere, angora and silk.

Like the delicates program, it washes clothes more gently than the normal setting, so they don't snag, matt or shrink.

Fuzzy logic and other automatic wash systems

Many washer-dryers have 'fuzzy logic' or AI sensors that automatically vary the wash program according to how big or dirty the load is.

Bioprofile, biostage or protein eliminators are just some of the names different companies call these stain-removing features. Aquatronic wash, 3D AquaSpa, Showerwize, Power Jet and other similar terms refer to features that spray water to soak clothes and distribute detergent more effectively.

All these features vary in how effective they are – check our washer-dryer reviews to see how each one scores in our tough cleaning tests.

To help you decide whether a washer-dryer is right for you, read our advice on washer-dryer or washing machine and tumble dryer: which is more cost-effective?