Should I use the eco wash setting?


The mysterious little eco button should give the most energy-efficient results, so why do we ignore it?

Are eco modes worth it?


Eco modes on our appliances should make it simple to choose the most energy-efficient path to clean clothes and dishes – but many of us shy away from them. Research in May 2017 showed that just 21% of those surveyed who use a dishwasher opted for the eco wash setting the last time they used it.

A review of the Energy Rating Label (ERL) in 2014 revealed that the number of stars in the sticker on appliances influenced over half of the surveyed consumers' final purchase decision, and nearly 30% used it to estimate the annual operating cost of the appliance. 

So what's holding us back from using eco settings, and how much do they really help?

In this article:

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What is the 'eco mode'?

Eco modes are a program option on an appliance that has a combination of settings to lower the energy and water consumption during use. Generally, there are three elements that the eco mode adjusts when it cleans your laundry and the dishes: 

  • temperature
  • time
  • water.

Higher temperatures generally mean better washing, and in the case of dishwashers, better drying too. But they also use more electricity. Eco modes often use lower temperatures and less water and compensate for this by washing for longer periods. A dishwasher in eco mode may forgo heating the plates and utensils to dry them off, and instead allow them to air dry.

Are eco modes standardised?

Eco mode settings act differently in different appliances and across different models. According to Petr Valouch, Testing Coordinator for Whitegoods at CHOICE, in Australia there's no standard definition of what an eco mode is or the savings it should deliver. Nor is there data on the efficiency of eco modes in appliances in Australia. It is left to the manufacturers to decide what is 'eco'.

Do eco modes help save money?

In 2015, CHOICE's counterpart in Germany found through its testing of dishwashers over the years that the eco mode, across different brands and models of dishwashers, has the lowest energy consumption, with the automatic and short programs consuming 20–30% more energy.

A subsequent literature review into the German study confirmed this, and also found:

  • fast clothes washing programs, or those with temperatures over 30°C, increased energy use by 30–100%
  • tumble dryers used without the auto-off sensor increased energy use by an average of 25%.

Tip: Detergents for dishwashers and washing machines can make up a third of the running cost of the appliance so it's important to make sure you use one that performs well.

Are eco modes used for the stars in the Energy Rating Label?

The program setting used for assessment for the ERL is nominated by the manufacturer and is not necessarily the 'eco' program, but it often is.

This is important because the cycle tested for the energy star rating must meet certain performance standard requirements, including adequately removing dirt from clothes or food waste from dishes.

For washing machines and dishwashers, the cycle setting or mode tested for the ERL must be declared on the sticker. When the eco mode is used for the ERL, it's an endorsement that the eco mode met the required performance standards under the prescribed conditions of that test.

CHOICE asked a number of manufacturers if their appliances were tested for the ERL using the eco mode.

A spokesperson for Electrolux said the eco mode was "generally" used in the ERL test for its products. Spokespeople for Miele and Omega, Blanco and Everdure said that the eco mode was always the mode tested for the ERL for their current models.

A spokesperson for Energy Rating told CHOICE, "When a clothes washer is tested, it is required to meet the standards as per AS/NZS 2040.2:2005, which requires a minimum water temperature of 35°C and is deemed a warm wash cycle."

Suppliers are also given the option of including a cold wash cycle on the ERL which does not require a minimum water temperature. If the cold wash cycle is included, a disclaimer is required to be displayed on the ERL stating that "cold washing performance has not been measured and is not guaranteed".

Are cold washes more energy efficient?

Yes, cold washes in washing machines deliver significant energy savings.

When CHOICE tests the energy and water consumption of washing machines, we run all the machines on a 'normal' cold cotton wash. We don't specifically test 'eco modes', because our regular surveys show you often don't use them.

We recently compared the energy savings in our tests of washing machines in cold cotton wash mode, with the savings from using the Energy Rating Label mode (commonly eco mode). We found that you can save around 25% more energy by choosing the cold wash mode over the ERL mode. That's cold power!

Spokespeople from Miele, Fisher & Paykel, Omega, Blanco and Everdure all confirmed that their appliances ran in the most energy and water efficient way in their eco modes with the coldest water temperature.

Is the rapid cycle more energy efficient than a very long cycle?

No, 90% of the energy used in a washing machine cycle is for heating the water.

All of the agitation and soaking during the long running washing cycle isn't chewing up much electricity. But the rapid hot wash, in the dishwasher or washing machine, will devour more electricity, so a cold and long wash is still efficient.

Will the 'eco' or 'auto' mode save more energy in the dishwasher?

CHOICE compared the energy costs of running dishwashers in 'auto' mode and in the mode tested for the Energy Rating Label (commonly eco mode) and found 'eco' mode will save more energy.

Households can make energy savings of approximately 30% if they instead run their dishwashers in eco mode. However, we test dishwashers in the 'auto' cycle where available because our members tell us that they tend to use this setting if they have it.

Tips for saving money, energy and water

Dishwashers

Choose models with:

  • high (over 3.5) water and energy star ratings
  • 'eco' options (they can save 30% on running costs)
  • delay-start feature to make use of off-peak tariffs or solar generation.

When operating:

  • select eco mode
  • wash only full loads
  • scrape plates clean, don't rinse.

Washing machines

Choose models with:

  • high (over 3.5) water and energy star ratings
  • 'eco' options
  • delay-start feature to make use of off-peak tariffs or solar generation.

When operating:

  • select eco mode with cold water, or a cold water cycle, unless dealing with oily stains
  • use an enzyme-based detergent because it's just as effective at lower temperatures
  • wash full loads or adjust the water level to suit the load size.

Tip: Front loaders generally use about 50% less energy than top loaders.

Looking for the best washing machine?

See our expert product reviews.

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