A hybrid heating system, which includes o a primary circuit of a primary heat generator, comprising in parallel at least one upper i.e. hot service water heat exchanger and one heating circulation heat exchanger to be heated with the primary heat, and a lower i.e. chilled service water heat exchanger advantageously connected in series together with the upper i.e. hot service water heat exchanger, so that the circulation of returning service water is connected between the upper i.e. hot service water heat exchanger and the lower i.e. chilled service water heat exchanger, o a heating circuit circulating circulation water in a controllable manner at the points of consumption via said heating circulation heat exchanger heated with the primary heat, o a heat pump unit comprising a compressor, an expansion valve, an evaporator and a condenser (36a, 36b) and connected so as to utilize a selected heat source with the evaporator as well as to simultaneously emit a secondary heat with the condenser in parallel with said heating circulation heat exchanger, wherein said heat source comprises at least one exhaust air heat exchanger and one cooling radiator, characterized in that the system includes, • in parallel with the heating circulation heating circuit, a heat-dumping heat exchanger for discharging heat to a specific thermal energy outlet circuit when there is no consumption at said points of consumption, • flow configuration means adapted to connect said exhaust air heat exchanger either a) as a heat source for the evaporator of the heat pump, or b) to connect said exhaust air heat exchanger to said thermal energy outlet circuit of the dumping heat exchanger as a heat sink, and simultaneously to connect the cooling radiator as a heat source for the evaporator. o a primary circuit of a primary heat generator, comprising in parallel at least one upper i.e. hot service water heat exchanger and one heating circulation heat exchanger to be heated with the primary heat, and a lower i.e. chilled service water heat exchanger advantageously connected in series together with the upper i.e. hot service water heat exchanger, so that the circulation of returning service water is connected between the upper i.e. hot service water heat exchanger and the lower i.e. chilled service water heat exchanger, o a heating circuit circulating circulation water in a controllable manner at the points of consumption via said heating circulation heat exchanger heated with the primary heat, o a heat pump unit comprising a compressor, an expansion valve, an evaporator and a condenser (36a, 36b) and connected so as to utilize a selected heat source with the evaporator as well as to simultaneously emit a secondary heat with the condenser in parallel with said heating circulation heat exchanger, wherein said heat source comprises at least one exhaust air heat exchanger and one cooling radiator, • in parallel with the heating circulation heating circuit, a heat-dumping heat exchanger for discharging heat to a specific thermal energy outlet circuit when there is no consumption at said points of consumption, • flow configuration means adapted to connect said exhaust air heat exchanger either a) as a heat source for the evaporator of the heat pump, or b) to connect said exhaust air heat exchanger to said thermal energy outlet circuit of the dumping heat exchanger as a heat sink, and simultaneously to connect the cooling radiator as a heat source for the evaporator. a) as a heat source for the evaporator of the heat pump, or b) to connect said exhaust air heat exchanger to said thermal energy outlet circuit of the dumping heat exchanger as a heat sink, and simultaneously to connect the cooling radiator as a heat source for the evaporator.