The thermo-hydraulic investigations for triple concentric-tube heat exchanger with two-thermal communications have been experimentally carried out at steady state conditions. Water at different temperature was passed through the inner tube, the inner annulus and through the outer annulus. Experiments were performed at all possible flow arrangements for Reynolds number ranging from 2800 to 11,000 of hot water in inner annulus. Validations of experimental results have also been carried out with the established results. Experimental investigations have been carried out to measure the variations in temperature of fluid streams along the length of heat exchanger and variations of friction factor and of Nusselt number with Reynolds number.