Excess molar enthalpies for the (ethanol + 1-propanol + tetrahydropyran) and (ethanol + 1-propanol + 1,4-dioxane) ternary mixtures and their binaries (ethanol + tetrahydropyran) have been measured by a flow microcalorimeter at 298.15 K and ambient pressure. The experimental results are correlated with a polynomial equation. The results have been compared with those calculated from a UNIQUAC associated-solution model. This model considers the self-association of like alcohols, cross-association of unlike alcohols, and solvation between alcohols and tetrahydropyran or 1,4-dioxane. The model with the association constants, solvation constants, and binary information alone could satisfactorily represent the ternary excess molar enthalpies.