The 2030 policy framework for climate and energy, proposed by the European Commission, aims towards the reduction of European greenhouse gas emissions by 40% in comparison to the 1990 level and to increase the share of renewable energy of at least the 27% of the European's energy consumption of 2030. The use of biomass as sustainable and renewable energy source may be a viable tool for achieving the above goals. However, renewable energy technologies are not totally clean because they cause energy and environmental impacts during their life cycle, and in particular they are responsible of air pollutant emissions. In this context, the paper assesses the energy and environmental impacts of a 46 kW biomass boiler by applying the Life Cycle Assessment methodology, as regulated by the international standards of series ISO 14040, ISO 21930 and EN 15804. The following life-cycle steps are included in the analysis: raw materials and energy supply, manufacturing, installation, operation, transport, and end-of-life. The results of the analysis, showing a life-cycle primary energy consumption of about 2,622 GJ and emissions of about 21,664 kg CO2eq, can be used as a basis for assessing the real advantages due to the use of biomass boilers for heating and hot water production.