The Heating and Ventilating Contractors Association's head of training, Tony Thomas, said the regulations were discouraging employers from taking on teenagers.
He said: "Nobody envisaged that this would be the case with the introduction of the working time regs, but feedback has been that employers are increasingly refusing to take on young people."
The HVCA has reported that M&E training schemes are oversubscribed, but that that the trainees are finding it difficult to find work in the industry.
Employers are increasingly refusing to take on young people
Tony Thomas, HVCA head of training
Thomas said: "There is a different problem in the regions, where public transport is not so readily available. Here, young people who have to commute long distances to work on site are refusing to do so if they are only allowed to work an eight-hour day."
Thomas said that he had been in talks with other industry bodies, such as the Construction Confederation and plumbing associations, and they shared his concerns.
Evidence will now be collated and representations made to government officials on the issue. Thomas said: "We will have to push for a review of funding for adult trainees. Contractors need to be convinced there is a business case for taking on young people."
Thomas contractors were becoming increasingly agitated about rising liability premiums, and whether insurance costs would rise if they hired young people.