Professional Installers. In every country of the EU, installers are qualified or their experience is recognised after 3 years of work, but a diploma is not always required to design, to install or to maintain the heating systems in existing building, especially towards to the small power. Also, even though there is regulation to maintain large power plants (maintenance which is not always applied for all large systems), there is no specific regulation to impose qualified persons to do the work5. The level of qualification & distribution of installers/designers on the market can be expressed as follows6: Installers 75% low level Technicians to install large power systems 15% technician Engineers to design 10% Engineer However for security and safety reasons and concerning a new installation of complete gas- fired heating systems (including boiler, duct, pipes) or electric installation, qualified and/or competent persons are required. Most of people who work on gas-fired equipment must have been suitably trained and must have achieved a Certificate in gas servicing. Their work is controlled and recent evaluations show that installations are better realized than in the past. Generally7, there is always no similar restriction on persons maintaining oil-fired or solid fuel fired heaters and boilers8. Also in some country, the electric sector, seems, to present a lot of realisations of bad quality by the lack of certificated servicing and control. Concerning solar and wood technologies, several countries have made a large effort to ensure a good quality of training and qualification of installers. This is of course very important for all new technologies which are getting place in the energy market. But note that, in some countries, bad or insufficient maintenance and lack of training of the installer has contributed to delaying the development of heat pumps or condensing boilers.
