Excess molar enthalpies H-E and excess molar volumes V-E have been measured at 298.15 K and 0.1 MPa for the ternary mixture tetrahydrofuran (THF) + propan-1-ol (PrOH) + n-heptane including the three binary mixtures using flow calorimetry and a vibrating tube densitometer, respectively. Molar excess Gibbs energies G(E) have been measured at 298.15 K using a static VLE apparatus equipped with a chromatographic sampling technique for the vapor phase as well as for the liquid phase. Experimental results have been compared with predictions of the ERAS model.