Householders are needlessly adding to their energy bills because of widespread myths about the most effective way to heat homes, a campaign group has warned.

Of the four fifths (78%) of Britons who think they understand how to use their heating controls, more than half (52%) turn up the thermostat during colder weather - an unnecessary move because the thermostat is designed to maintain a constant temperature whatever the conditions outside.

The survey, carried out for the Big Energy Saving Week campaign between the Energy Saving Trust (EST), Department of Energy and Climate Change and Citizens Advice, also found 38% think it is more energy efficient to leave the heating constantly turned on at a low temperature - simply meaning the home is heated when there is no one there to benefit and too cold when people are inside.

And more than a third (35%) turn their room thermostat up when they want to heat the space faster, which only sends the temperature higher but no more quickly.

Almost a third (31%) leave their water heating on all the time to make sure they never run out, which could be costing more than necessary, and just 38% fully understand how electric storage heaters work by taking advantage of cheaper night rates.

Research by the EST also found many households are still not regularly switching energy supplier, with just a quarter (24%) of bill payers claiming to have switched in the last year.

The poll found 74% of Britons remain concerned about their energy bills, while the three organisations involved in the campaign said households could save £75 a year by learning to heat their homes efficiently.

EST chief executive Philip Sellwood said: "Rightfully, millions of householders are confused by their heating controls because, let's be honest, it is a bit of a minefield.

"There are plenty of myths out there and it's no wonder people aren't getting it right. We are urging customers to learn about the myths, check their tariff, switch suppliers and insulate their homes."

Energy and Climate Change Secretary Ed Davey said: "The easiest way to cut energy bills fast is to shop around for the cheapest energy deal and switch suppliers.

"Thanks to government action to reform the energy market the number of independent suppliers has almost trebled since 2010, encouraging greater competition which helps drive down prices.

"We're also making it easier and quicker for people to switch, and the major energy suppliers have confirmed that switching times will halve by the end of this year to just two and a half weeks."

Citizens Advice chief executive Gillian Guy said: "Every day, we help people who are struggling to meet the cost of their energy bills.

"Eighty thousand people a year come to us for help with fuel debts. With prices up a third since 2010, it's more important than ever that people know what they can do to keep their fuel bills down and what help is available.

"That's why we're running events up and down the country to help people make sure they are not paying a penny more than they have to."

:: Ipsos Mori surveyed 2,418 people online between September 23-26.