Summary:

The article contains problems of impact of geothermal water chemical composition on technical devices of heating plant in Pyrzyce, and therefore the costs of its operation. The paper presents geothermal water resources in Poland and characteristics of water deposit in Pyrzyce.
On the basis of the water chemical composition research and exploitation documentation an evaluation of influence on heating plant has been made. Based on the analysis, very high water mineralization of 115,00 g/dm3 has been found. It has caused pipes corrosion and silting-up holes despite the use of technical solutions for the construction of installations. In result, the increase of provided exploitation and energy costs has been observed.