Residents are being warned to be on their guard after forceful cold calling sales techniques have been used to offer loft and wall insulation.
Trading Standards have received reports from people living in Blackburn saying they have been contacted by salesmen using pressurised marketing ploys.
The caller informs residents that they must have their loft insulation increased as it is a legal requirement. Trading standards chiefs have warned this is simply not true.
In each instance the salesman claimed to be calling on behalf of "energy supply companies" and did not leave a trading address, just a name and only an 0808 number.
Trading Standards say it is possible the bogus traders are trying to make money on the back of the Council's new initiative offering loft and wall insulation from only £99 each. The Council is working with Bookmysurvey and the installation company HIS. The bogus company is selling their product for double the Council's price.
Homeowners are being urged not to deal with unknown traders.
Paul Heward, the council's principal officer for consumer protection, said: "This appears to be a scam because there is no legal requirement to have your loft insulation increased.
"The public protection service would always advise the public to be wary when traders attempt to sell products over the phone or at the door.
"We would also ask that members of the public make our older citizens aware of this potential scam.
"Enquiries are ongoing to ascertain where the calls are emanating in order to eliminate this problem at source."
Anybody concerned about this issue or wanting to book a free survey for the discounted insulation service can contact Nicole Cook, the council's senior housing officer on 01254 588863.