Conceptual planning (technical, economical and politic feasibility) of geothermal district heating systems is the most important step of these projects. In this study, a conceptual planning model developed for geothermal district heating systems is applied to the project of Balcova (Izmir) System-2 Geothermal District Heating System which is on the agenda nowadays in Balçova and the technical, economic and politic feasibilities are investigated. The city section on which the geothermal district heating system will be constructed has a maximum capacity of dwellings having an area of 391,700 m2 and 80% of them have been built and are in use. The most important parameter that affects the economics of the geothermal district heating systems is the participation ratio of the dwellings in the district. In this study different participation ratio (between 100% and 26%), participation costs (between 1250{dollar} and 1500{dollar}) and participation periods (2 or 5 years) are considered and the monthly fixed energy charge which will make the internal rate of return ratio approximately positive values around 0% are calculated.