When Swaminarayan temple, Sokhda planned for NRI Hostel they needed 24 hrs hot-water in each bath-rooms attached to each rooms. They had lot of waste-wood. We therefore designed a wood fired thermic fluid heater with hot water Tank on the hostel terrace heated with hot thermic fluid. An interface of hot water / thermic fluid was necessary to avoid scaling of hot-water pipelines at high-temperature above 60°C. The system consisted of