Abstract: Device for expansion transfer in liquid cycle systems, in particular for heating installations, comprising a heating boiler (1), a liquid line (2, 2'), radiators (3) and an expansion vessel (4) at atmospheric pressure. The expansion vessel (4) is connected to the liquid line (2) of the heating installation through an inlet line (5), an outlet line (6), an overflow valve (7) which can be adjusted according to the operating pressure of the installation, and a continuously operating circulating pump (9).