The appliance is either Energy Star Certified, or has an EU energy efficiency rating of A++ or A+++. This means it consumes around 20-30% less energy than is required by the minimum local standards for energy efficiency.
Hoover OPH 716DF
The more power per year a device consumes, the less energy efficient it is, making it more costly over time.
Whirlpool AWE 8840
Stackable machines are ideal if you have limited space as you could stack a tumble dryer on top of a washing machine.
Front loading machines are good as you can use the space above and sometimes stack a dryer on top. In general front loading machines use less energy, using less water by only partly filling the drum and obtaining higher spin speeds which clean without requiring as much heat.
Dot matrix displays can show important text or graphics using a matrix of lights or mechanical indicators like the display on a calculator.
With a transparent door you can look inside the machine and see what laundry is inside.
You can adjust the height of the machine which means that if the floor is uneven you can level it out.
A reversible door is useful if the machine is in a corner, so you can make it open more conveniently. It also means the door is easy to remove and can be replaced if needed.
A faster spin speed means you can get things cleaner with a lower temperature of water. Using a fast spin also extracts water, meaning that the clothes come out nearly dry. Generally, anything over 1000 rpm is very good.
Machines with a load sensor can weigh the load and adjust settings accordingly. This means you don't have to feel as guilty about doing a smaller load as the machine will use less water.
With a wider range of programs to choose from you can be more specific and choose the best, most economic program for your needs.
With a bigger drum you can fit in larger items such as duvets, or do a big load at once.
With a delay start option you can schedule the machine to begin at a later time. You can also set the machine to wash at night if your electricity is cheaper outside of peak times.
The machine will let you know when it is finished with an alarm or even by playing a tune.
Any faults with your machine can be detected and diagnosed at an early stage with a smartphone. The machine will send a signal indicating what is wrong and how to fix it, without you having to call for help.