The article proposes a scheme for using a lithium bromide absorption thermotransformer (LBATT) with two-stage absorption for deep utilization of the heat of combustion products (CPs) of gas boilers. At the same time, this solution allows heating the dictrict heating systems return water in the cold season. In the warm season, LBATT is used to cool the water of the air conditioning system or process equipment cooling. In this case, heat removal from LBAHT with two-stage absorption in the warm season is carried out using an drycooler. The analysis of the effectiveness of the use of LBATT in the cold and warm seasons is carried out. The theoretical transformation coefficient of LBATT with deep utilization of flue gases reaches 1.72. The theoretical thermal coefficient of LBATT when cooling water in the warm season reaches a value of 0.7.