Most households with a dishwasher admit to pre-rinsing their dishes before loading them, according to a new study.
But according to Utilita Energy, “double washing”, along with not switching to eco mode, is costing families £450m a year.
Three in five households rinse first at the cost of around £38 a year when using hot water, and £11 when using cold, the energy supplier found.
For the almost a third of households who use their dishwasher twice a day (31%), the associated costs will double to £76 and £22, respectively.
The average cost of double dishwashing is £25.48 per household, which wastes 4,576 litres of clean water each year – across all households that’s 2,422 Olympic-sized swimming pools of clean water each year.
On average, “double dishwashers” rinse for from 30 seconds up to two minutes each time, with two in five households (42%) admitting to rinsing items until they are sparkling clean, despite the machine having a rinse mode.
The study revealed that three in five households have never used their dishwasher’s eco mode (62%), which has the power to save each household £34 a year, on average.
Almost half of all dishwasher households have never changed the machine’s settings at all (46%).
But why is pre-rinsing so popular?
According the Utilita’s behaviour study the top five reasons were:
- Concerned about clogging the dishwasher – 59%
- Want to keep the dishwasher clean – 39%
- To avoid breaking the machine – 39%
- It’s a force of habit – 37%
- To avoid the dishwasher smelling – 30%
But households who choose not to pre-rinse gave the following rationale:
- It’s a waste of water – 59%
- Pointless when the machine rinses them – 53%
- My dishwasher has a rinse on the cycle 31%
- My dishwasher tablets advise not to rinse – 25%
- I can’t stand touching dirty plates – 7%
Utilita’s head of sustainability, Archie Lasseter, said he hoped the information campaign would encourage people to put confidence in their machines and save money and the planet in the process.
“Knowing what our habits are costing us can encourage us to reconsider our behaviours, and in this case, the savings are significant, so should hopefully make households think twice,” he said.
“We can tell households how much money they’ll save, but until they load the dishwasher without pre-rinsing, and see positive results every time, they won’t be convinced.”