Energy experts have told households that running washing machines and dishwashers at certain times of day only reduces bills for those on time-of-use tariffs such as Economy 7. For everyone else on a standard single-rate tariff, the time of day makes no difference to the cost.
The advice comes as the energy price cap rose by 4% on October 1, pushing the average annual bill for direct debit customers on a standard variable tariff to £1,723, or about £144 a month, with these rates in place until December 2026. The increase is largely driven by higher gas prices, with the price of a unit of gas jumping 8.7%, while electricity rose by less than 1%.
What the experts said
Gareth Kloet, an energy specialist at Go.Compare, said washing machines and dishwashers are among the most energy-intensive appliances in the home. He explained that using them during off-peak hours can reduce costs, but only for customers on a time-of-use or dual-rate tariff. "Be sure to check the details of your tariff to find out what rate you're on and whether it includes different price bands throughout the day," he said.
Simon Bones, founder and CEO of Genous, a home retrofit company, said some suppliers offer time-of-use tariffs where electricity prices change by time of day. He noted that the cheapest times vary between suppliers, so customers need to check their tariff details first. He also suggested that homes with many electricity-hungry appliances could consider a home battery, which charges when electricity is cheaper and powers the home when prices are higher, though installation costs can be high.
Check your tariff first
Richard Howarth, laundry product manager at Hoover, Haier UK & Ireland, said there is no single best time of day to run appliances; it all depends on the tariff. He emphasised that the biggest savings come from using lower temperatures (20–30°C where possible), running full loads, and selecting the Eco program, since heating water uses the most energy in a wash.
Ana Padilla Martinez, e-commerce and marketing specialist at Plumb2u, agreed that for most UK households, the time of day won't affect energy costs. "If you are on a standard single rate tariff, and most people still are, a unit of electricity costs exactly the same at 3am as it does at 6pm. Running the dishwasher overnight saves nothing," she said. She added that fire services advise against running washing machines, dishwashers and tumble dryers overnight or when out of the house, so a delay timer that finishes while people are awake is the sensible option.
Other ways to save
Ana also recommended running washing machines at lower temperatures and dishwashers on eco cycles, which use less water and heat. Regularly cleaning appliances can help too, as limescale on heating elements makes them use more electricity. She suggested running a hot maintenance wash with descaler every few months and using the right amount of detergent for local water hardness. Cleaning filters also helps, since a blocked filter makes the machine work harder and wastes energy.
She also advised checking flexible inlet hoses if they are more than five to 10 years old, not for energy savings but because a burst hose in autumn could lead to costly damage. On full loads, she said: "Two half loads use close to twice the water and twice the heating of one full one. It is the least interesting tip on the list and it saves more than the clever ones."
