Fraudsters are using the government's Green Deal energy-efficiency scheme to con households out of cash - in many cases by as much as £500.
Citizens Advice has reported that 70% of the consumer queries it receives regarding the Green Deal are about scams.
The Green Deal allows people to install energy efficiency improvements to their home without having to pay for them upfront but there is often a charge for an assessment, through which the homeowner finds out what improvements they could make. The assessment fee is what the scammers have jumped on.
Citizens Advice said more than half of Green Deal scam victims it has spoken to were contacted out of the blue - by phone or a knock at the door - and offered thousands of pounds worth of home improvements for free.
But victims have lost up to £500 after paying a fee for assessments that never took place, or if it did the victim didn't receive any further contact from the company.
Other victims have been asked to provide their bank details for an assessment fee to be refunded, only for more money to be taken from their account.
If you have been a victim of a scam, let us and others know by clicking the link here.
Citizens Advice is calling for a ban on cold calling and doorstep selling of the Green Deal to protect people from fraudsters. Chief executive Gillian Guy said: "The Green Deal is at risk of being undermined by fake firms. With energy prices up by 33% since 2010, households are looking for ways to save money on their bills.
"Opportunistic tricksters are lining their pockets by ripping-off people who are trying to cut the cost of heating and lighting their home."
She added: "A more energy-efficient home can drive down the cost of bills so it is important people look out for scams and action is taken to protect consumers. A ban on cold calling and doorstep selling of Green Deal would help people distinguish between the genuine scheme and a scam. Consumers can check whether a firm is a proper Green Deal seller by looking at the authorised list of companies."