The paper presents a comparative analysis of five systems for hot water for a family of four. To select the best possible final energy consumption was calculated for the hot water and then carried out technical and economic analysis based on dynamic methods, such as LCC, PBP, NPV and IRR. As a result of the calculations it has been selected the system, which in the perspective of admitted 20-year period of use is characterized by the best economic indicators. Total costs of hot water for this system are the lowest. The best solution is to use a gas hot water heater capacitance, for which the index values are the best, and most importantly, this investment will return after 4 years. Application of heat pumps and solar set with flat collectors is a good solution, however, investment in these devices will return only after 13-14 years.