Dishwashers: How to buy the best dishwasher Dishwasher water and energy use

Washing plates and dishes with a dishwasher uses less water than washing by hand. The main wash program on a full-sized dishwasher uses about 16 litres of water – that’s less than two washing-up bowls full – and will clean more than 120 items. 

But a large domestic appliance like a dishwasher is still going to use energy, which will be reflected in its running costs. 

If you want to be greener with your dishwasher – and save money on bills in the process – here's how to reduce its environmental impact.

We test dishwashers with an everyday load of dishes

Buy the cheapest-to-run dishwasher

Dishwashers add £££s to your electricity bills, but in Which? tests we've found that the amount energy dishwashers need to do a good job varies dramatically. Our dishwasher energy costs calculator reveals how much dishwashers cost to run, as well as how much dishwashers currently on sale in shops will cost you over their lifetime.

Loading dishwashers

When you’re using your dishwasher, aim for a full load each time. But be careful not to overfill it, as this could prevent some items from getting cleaned properly. 

Large items should go at the back and sides of the racks – if big plates are at the front this can stop the water reaching the detergent dispenser.

Saving water when dishwashing

Run your dishwasher on its energy-save or eco program. It'll take longer than the main program to get your dishes clean, but uses about two litres less water. And if you wash your dishes without soaking or pre-rinsing, you’ll save even more water.

Energy saving dishwashing

Energy-save or eco programs also use the least amount of energy. They wash dishes at lower temperatures, so don’t need as much energy to heat the water. 

On average, energy save programs use about 20% less energy than the main program.

Green dishwasher detergents

Try using green dishwasher detergents that are free from petrochemicals, phosphates and chlorine. Their performance can be variable so they might not always be suitable, but their green credentials check out.

Cheap electricity

Some electricity tariffs charge less per unit at night than in the daytime – if you’re on such a tariff, using the delayed-start function to run your machine at night will knock some money off your electricity bill.

Greener dishwashing video

For more advice on how to save water, energy and be green with your dishwasher, take a look at our how to be green with your dishwasher video.

Dishwashers reviewed by Which?

Which? has tested and reviewed 130 dishwashers from manufacturers including AEG-Electrolux, Bosch, Electrolux, Miele, Hotpoint, Whirlpool, Zanussi. 

Check out the 130 Which? dishwasher reviews for the latest Best Buys.