Several years ago it has been demonstrated experimentally and verified theoretically that Vuilleumier heat pump systems (a combination of a Stirling engine with a Stirling heat pump) can be supercharged periodically by means of an attached resonance tube, thus enhancing the pressure variation and the power density of such units. These investigations have been continued in the present study, where it has been shown that the supercharging stabilises the movement of the free piston. High performance rates can be achieved at full power as well as in a wide range of part load conditions. Supercharged Vuilleumier heat transformers thus meet with the many requirements which are imposed upon a domestic heating systems; their widespread application can be envisaged, what will result in substantial energy savings as compared to conventional heating systems.