Professor Hajo Funke, an expert on far-right extremism from Berlin's Freie University, said the main problem was that those who wanted to leave did not trust the body that was organising it.
Craig Funke, chief executive and part owner of Equiguard, which provides warranties to the heating and cooling industries, says geothermal units' failure rates, including both equipment failure and bungled installs, are equal to those of conventional equipment.