Provided is a heating and hot water supply device. The heating and hot water supply device includes: a combustion part; a heat exchanger; a circulation passage; a circulation part; a bypass passage; a distribution means for distributing the heating medium to the circulation passage and the bypass passage; a hot water supply heat exchanger; a water supply passage; and a hot water supply passage (21). The distribution ratio of the distribution means is adjustable so as to correspond to a heating operation, a hot water supply operation, and the simultaneous heating and hot water supply operation. The heating and hot water supply device includes an operation part, which heats the heating medium to one or more heating terminal setting temperatures and circulates the heating medium, and switches a setting of the one or more heating terminal setting temperatures to be increased by a prescribed temperature during the simultaneous heating and hot water supply operation.

A secondary heat exchanger includes a case and a first heat transfer tube portion. The case includes a box body and a first closing member. The box body is provided with a second opening on one side in a third direction. A first assembly in which the first heat transfer tube portion and the first closing member are assembled integrally is mounted to the box body so that a plurality of first heat transfer tubes are is inserted into the box body from the second opening and so that the second opening is closed by the first closing member.

The present invention provides a water heating device capable of shortening a flow passage that mixes hot water and cold water and saving space in the device. In a flow path cross section of circular orthogonal to the central axis of the flow path, the flow inlet has an outer wall extending from the inner peripheral surface of the flow path in a direction of a tangent of the inner peripheral surface, and the central axis of the flow inlet is disposed closer to the inner peripheral surface of the flow path connected to the outer wall with respect to the central axis of the flow path.

A domestic water heating group includes a heat source; storage tank. A heat exchanger includes inlet and outlet sections, the the inlet and outlet being in fluid communication with: a water supply system, a water usage system and the tank. The water is heated to, towards the tank, a storage temperature TAC and/or towards the usage system at a supply temperature TER, mixer group is upstream of the inlet of the exchanger group and has first and second inlet ports connected to the supply system, tank, exchanger group The mixer receives the domestic water, at a low temperature TIN, the heated domestic water at the second inlet port, and mixes the water thus received and provides at the outlet port, in fluid connection with the exchanger group, the mixed domestic water having an intermediate temperature TINT included between the temperature TIN and the temperature TAC.

Provided is a heating and hot water supply device The heating and hot water supply device includes: a combustion part; a heat exchanger; a circulation passage; a circulation part; a bypass passage; a distribution means for distributing the heating medium to the circulation passage and the bypass passage; a hot water supply heat exchanger; a water supply passage; and a hot water supply passage (21) The distribution ratio of the distribution means is adjustable so as to correspond to a heating operation, a hot water supply operation, and the simultaneous heating and hot water supply operation. The heating and hot water supply device includes an operation part, which heats the heating medium to one or more heating terminal setting temperatures and circulates the heating medium, and switches a setting of the one or more heating terminal setting temperatures to be increased by a prescribed temperature during the simultaneous heating and hot water supply operation.

A secondary heat exchanger includes a case and a first heat transfer tube portion. The case includes a box body and a first closing member. The box body is provided with a second opening on one side in a third direction. A first assembly in which the first heat transfer tube portion and the first closing member are assembled integrally is mounted to the box body so that a plurality of first heat transfer tubes are is inserted into the box body from the second opening and so that the second opening is closed by the first closing member.

A water heater includes a plurality of stages of burners, a water supply pipe, a hot water outlet pipe, a heat exchanger, a passing water quantity control unit, a temperature detection unit, and an operation control unit. The operation control unit, upon confirmation that a predetermined start condition of a passing water restriction is satisfied at a start of a hot water supply, performs the output hot water temperature control by calculating a target flow rate that causes no switching or a minimum count of switching of the combustion stages of the burners and configuring the passing water quantity control unit to have the target flow rate. The operation control unit, upon confirmation that a predetermined release condition of the passing water restriction is satisfied, executes the passing water control in which the passing water quantity is returned to the predetermined water quantity by gradually releasing the passing water restriction.

A hydro-furnace for an RV includes a housing, a water inlet and a hot water outlet accessible through the housing, a radiator tank inside a radiator compartment of the housing, a heat exchanger inside a burner compartment of the housing for heating water flowing therethrough, a burner inside the burner compartment to provide heat to the heat exchanger, a heater core inside a recirculating compartment of the housing or heating air flowing therethrough, a blower inside the recirculating compartment for pulling return air through the heater core and delivering heated air outside the housing, and a pump circulating water from the radiator tank through the heat exchanger, through the heater core, and back to the radiator tank.

A water heater includes a plurality of stages of burners, a water supply pipe, a hot water outlet pipe, a heat exchanger, a passing water quantity control unit, a temperature detection unit, and an operation control unit. The operation control unit, upon confirmation that a predetermined start condition of a passing water restriction is satisfied at a start of a hot water supply, performs the output hot water temperature control by calculating a target flow rate that causes no switching or a minimum count of switching of the combustion stages of the burners and configuring the passing water quantity control unit to have the target flow rate. The operation control unit, upon confirmation that a predetermined release condition of the passing water restriction is satisfied, executes the passing water control in which the passing water quantity is returned to the predetermined water quantity by gradually releasing the passing water restriction.

A hot water-centered hot water and heating combination boiler includes: a cold water inflow tube through which cold water flows in; a main heat exchanger which heats the cold water flowing in through the cold water inflow tube by using the combustion heat of a burner; a hot water discharge tube which discharges the hot water heated in the main heat exchanger; an auxiliary heat exchanger which supplies heating water during a heating mode, in which heating consumption place, and causes heat exchange to occur between the heated water in the main heat exchanger and the lowered temperature returning water, in which the heating consumption place; and a control part which controls the combustion of the burner during a hot water mode and heating mode.