Single pan thermal analyses (SPTA) have been performed on Cu–14.5 wt.% Sn, Cu–21.3 wt.% Sn and Cu–26.8 wt.% Sn peritectic alloys. For this purpose, a SPTA assembly has been built and calibrated. As the latent heat is a function of temperature and composition during solidification of alloys, a new heat flow model coupled to a Cu–Sn thermodynamic database has been defined for the calculation of the corresponding evolutions of the solid mass fraction. To verify the accuracy of this model, a close comparison with a microsegregation model that includes back-diffusion in the primary solid phase has also been conducted successfully. The thermal analyses have finally shown that the Cu–Sn phase diagram recently assessed in the review of Liu et al. is the most reliable.