Domestic boilers. For domestic boilers, there is no regulation, compelling the regular testing of heating systems efficiency in existing building, except in Germany and Italy. But for reasons of safety, regulations impose annual checks of the combustion of the boiler, and chimney sweeping of the duct by competent contractors in the major of the European countries. In other cases, there are guidelines (safety guidelines) that encourage people to do yearly maintenance /inspection11. The application by the consumer of this periodic maintenance, required by this regulation, is not controlled. In Germany, Energy saving rules say that heating systems bigger than 50 kW have to be serviced twice a year. The service has to be made by qualified personnel. The rule called “Kleinfeuerungsanlagenverordnung” defines that existing boilers have to be retrofitted or exchanged up to 11/1/2004 (see chapter above). The planned “Energieeinsparverordnung” defines that boilers installed before October 1978 have to be exchanged up to the end of 2005. Except for recent retrofitted boilers that to be exchanged until the end of 2008.
