To provide a storage type heating unit which requires a small area for the installation.

In the storage type heating unit 1, a liquid-liquid heat exchanger 15 for heat exchanging between a first hot water circulation circuit 12 for circulating hot water stored in a hot water storage tank 11 and a heating circulation circuit 14 in which hot water flows from a heating radiation unit 3 is arranged above the hot water storage tank 11, and a circulation pump 16 is arranged in the first hot water circulation circuit 12 on the downstream side of the liquid-liquid heat exchanger 15. A return passage 18 which communicates the hot water storage tank 11 with an gas-liquid separator 17 is provided so as to return gas separated by the gas-liquid separator 17 provided to intervene in the first hot water circulation circuit 12 between the liquid-liquid heat exchanger 15 and the circulation pump 16 to the hot water storage tank 11. The return passage 18 is provided with a solenoid valve 19 for closing the return passage 18 during the operation of the circulation pump 16.