The article presents problems of maintaining the Z-type supply pumps and network operated in ENEA Wytwarzanie Sp. z o.o. Heat Segment, Białystok Branch with the use of thermovision and vibrodiagnostic studies. The practical aim is to select parameters of the supply pumps (multistage) which ensure energy efficient operation despite a serious operational wear - a 20-year working period. Commissioning of a Z-type feed pump and thermovision tests of selected machine construction elements constituted the subject of the research.