Millions of Brits are being urged to make a simple change to their boiler settings that could save them £112 a year.
Money-saving charities Nesta and Which? have launched a campaign with energy firms EDF, E.ON Next and Octopus to make a dent in soaring bills this winter.
Nesta says people with combi gas boilers should have it set to a “flow temperature” of 60C or below, to use the gas in the most efficient way possible.
But many boilers run hotter than that - which uses more gas as heat is lost from the pipes in your home.
Research has shown many people don’t know they can reduce their bill by turning the boiler temperature down.
While the majority of people have lowered their thermostat, ONS data shows only 1 in 10 lowered their boiler flow temperature in the last year.
The boiler flow temperature is different to your thermostat.
It is generally controlled by a dial or buttons on the front of the boiler - you can see exactly what to do by visiting moneysavingboilerchallenge.com.
People who run their boiler at a lower temperature will need to leave the heating on for longer to heat up their homes - around 15 minutes, Nesta said.
But research for the charity found despite this, lowering the flow temperature from 80C to 60C can save 9% of total gas use, or £112 for an average home.
Nesta claimed if 10million households with combi boilers reset their flow temperature to 60C, it would cut £1bn from energy bills and save 1.7million tonnes of carbon.
It would also save the Treasury around £500million - because gas bills, which are being subsidised by the government until 2024, would be lower.
Madeleine Gabriel, Director of Sustainable Future at Nesta, said the £112 was bigger than most better-known energy saving tips.
She added: “While the Energy Price Guarantee is helping millions to avoid financial ruin from high energy bills, the actual amount people pay still depends on their energy use.
“So it is important that anyone needing to keep costs as low as possible this winter feels confident taking action.
“Many people are already doing as much as they can to save money on energy bills.
“But there are hidden tricks that people can take themselves that don’t affect their comfort.”
Two thirds of people (67%) polled by the charity’s Behavioural Insights Team said they will wear warm clothes instead of turning on the heating in their homes this winter.
Some 57% said they would keep the heating on for fewer hours, 46% said they would lower the thermostat and 12% will put foil or reflectors behind radiators.
The intervention from Nesta, which was a public body until 2012, comes after Liz Truss rebuffed pleas to launch a £15m government-backed energy saving campaign this winter.
According to The Times, the "light touch" proposals signed off by Business Secretary Jacob Rees-Mogg included advising Brits to lower boiler temperatures - as recommended today.
It would have also involved turning off radiators in empty rooms and turning off the heating when people go out in a bid to save up to £300.
But on Friday Climate Minister Graham Stuart said "we're not a nanny-state Government" and suggested the government will not be advising the public to save energy this winter.
It came despite a warning from National Grid of potential blackouts lasting three hours at a time if gas supplies run low in an extreme scenario.
Shadow Levelling Up Minister Matthew Pennycook said it would have cut the risk of blackouts and that Ms Truss's stance was "absolute lunacy". Former Tory minister Guy Opperman said he was "fully behind" an energy saving campaign and insisted the government "must act".
A Cabinet minister yesterday said the UK Government is planning for blackouts but it is an "extremely unlikely scenario".
Chancellor of the Duchy of Lancaster Nadhim Zahawi said it is "only right that we plan for every scenario", before ruling out a £14 million campaign advising people how to conserve energy.
Planned blackouts hit the UK during the 1970s in response to the miners' strikes and the oil crisis.
There have also been major unplanned outages during storms, including in 1987 when more than 1.5 million people were left in the dark.
