on heating a liquid at it's boiling point,heat energy is converted to potential energy.why?

At boiling point the energy supplied to the particle is utilised to increase the K.E and overcome the interparticle forces completely and the particle is set free i.e. vaporises. However after the particle is set free the High K.E is converted to P.E due to lack of any acting forces on the particle. Thus, it leads to increase in Potential energy.