Several computer programs for estimating the economic potential of geothermal district heating systems are considered. The intent of the several programs is first reviewed. Then, computer program results from each of the models for several specified test evaluation cases are presented and compared. These comparisons reveal that the models indicate the same general trends but in general do not agree closely enough in absolute value of results to instill a feeling of confidence in the correctness of such results by potential users of the models. Finally, comparisons of piping costs used in several of the models are compared to other pipe costs derived from consulting engineers and general literature values.