Geothermal sources could provide society with clean and renewable energy nearly eternally. Geothermal district heating, in particular, could play a significant role in the energy transition. Although the application has been implemented to some extent, further upscaling is challenging due to various economic, technical and institutional conditions, resulting in barriers. This thesis presents a comparative, qualitative analysis of these barriers for three European countries (Germany, Hungary and The Netherlands). Through Energy statistics analysis, document analysis and interviews with experts in the field, these barriers are identified, decomposed, and their impact is analysed. It was found that barriers causing economic non-viability of geothermal district heating, poor insulation of buildings, and various regulatory and legal barriers are significant factors that prevent further upscaling. Finally, a set of policy recommendations is presented with the ambition to achieve a ten per cent share of geothermal district heating in the household, public and commercial services heat sector of these countries by 2030. To that end, European countries' governments are recommended: to restructure heat price regulation schemes; to reduce subsidies for conventional heating systems; to increase and reserve subsidies for geothermal district heating specifically; to provide attractive incentives for energy efficiency improvements in buildings; and to establish clear legal and regulatory arrangements for geothermal district heating systems.