The present invention relates to a hot water boiler using frozen gas, and more specifically, to a hot water boiler using frozen gas, which operates a freezing compressor for frozen gas circulation used in a refrigerant circuit to heat water in a hot water tank constituting a hot water boiler to use the water. The hot water boiler using frozen gas comprises: an operating pump operated by operation of a control box; a first electronic valve opened and closed by control of the control box when the operating pump is operated; an electric water heater to receive water in a hot water tank flowing into the hot water tank by opening the first electronic valve; a water-cooling vaporizer case to receive hot water by the electric water heater through a second electronic valve; a circulation pump installed in a water-cooling vaporizer to operate when water in the water-cooling vaporizer case reaches a prescribed temperature; a freezing compressor to supply hot water to the hot water tank by operation of the circulation pump and operate by control of the control box; and a primary condenser to receive warmed frozen gas by absorbing surrounding warm air while the frozen gas received through an expansion valve connected to a refrigerant pipe installed in the water-cooling vaporizer case and embedded in the freezing compressor flows. Liquefied refrigerant produced by discharging high temperature heat contained in refrigerant gas to the outside through a heat radiation pipe of the primary condenser is supplied back to a dehumidifier and the freezing compressor to form a refrigerant cycle. The primary condenser is embedded in the hot water tank. An outlet of the heat radiation pipe of the primary condenser is connected to an inlet of a heat radiation pipe of a secondary condenser to connect the dehumidifier and the freezing compressor to an outlet of the heat radiation pipe of the secondary condenser.
