Abstract: Provided is a miniaturized water heater having a plate type heat exchanger. The water heater includes a combustion device generating combustion gas by burning fuel; a heat exchange device heating hot water by heat exchange with the combustion gas; and an exhaust part exhausting the combustion gas after heat exchange. The heat exchange device includes a plate laminate in which vertically standing plates are laminated with gaps, and the hot water is heated by alternately flowing the combustion gas and the hot water through the gaps of the plate laminate. The combustion gas flowing in a vertical direction from the combustion device is introduced vertically or substantially vertically into an introduction part provided on a combustion device side of the plate laminate, and a flow direction of the combustion gas in the plate laminate is reversed to discharge the combustion gas to the exhaust part.

Abstract: A communication system includes housing equipment, a relaying apparatus that communicates with the housing equipment, and a management device that communicates with the relaying apparatus via a communication network. The management device is configured to store user identification information sent from a communication terminal that communicates with the management device via the communication network, and association information associated with identification information of the relaying apparatus sent from the relaying apparatus, and permit first communication via the management device between the communication terminal and the relaying apparatus that have been associated with each other in the association information.

Abstract: A hot water device includes a heat exchanger and an apparatus to which the heat exchanger is to be connected. First and second cases for the heat exchanger and the apparatus to which the heat exchanger is to be connected include first and second flange portions laid over each other and welded together. The first and second flange portions are each demarcated into a corner flange portion corresponding to one of first and second corner portions, and into a non-corner flange portion other than the corner flange portion. The non-corner flange portions protrude more to the outside of the first and second cases than the corner flange portions.

Abstract: A water heating device includes: a heat exchanger having a case to which heating air is supplied, and heat transfer pipes accommodated inside the case; and a straightening vane arranged on the downstream side in a heating air flow direction of the heat transfer pipes, and having a plurality of vent holes. The heat transfer pipe includes a plurality of pipe body portions that extend along a direction intersecting the heating air flow direction and approach the straightening vane. The plurality of vent holes are arranged so as to overlap the plurality of pipe body portions in the heating air flow direction.

Abstract: When a hot water supply operation is started, a single mode is used in which hot water is output only from a second hot water supply circuit of a water heater, by cut-off of a flow path in a first hot water supply circuit of a space-heating water heater by a cut-off mechanism. When a load imposed by hot water supply by the second hot water supply circuit increases during the hot water supply operation in the single mode, the cut-off mechanism is opened to start hot water output from the first hot water supply circuit and a hot water supply operation in a parallel mode is performed in which hot water is output from both of the first hot water supply circuit and the second hot water supply circuit.

Abstract: A communication adapter for collecting various kinds of information from a water-heating system and providing the information to an administration center via a wireless LAN router functions as an access point for providing a direct wireless communication with a smartphone; in response to a request from the smartphone via the direct wireless communication, it provides pairing authentication information to the smartphone; in response to a request from the smartphone, it initializes the wireless LAN connection information for the wireless LAN router to disconnect the wireless link to the wireless LAN router; and, when the wireless LAN connection information is set by its WPS function, it establishes a wireless link to the wireless LAN router and transmits the pairing authentication information to the administration center via the wireless LAN router.

Abstract: Provided is a heat exchanger which includes a plurality of meandering heat transfer pipes that includes first and second heat transfer pipes, as the plurality of heat transfer pipes, which are adjacent to each other in a predetermined y direction and are misaligned with each other in a z direction such that a plurality of straight pipe parts are in a non-overlapping state in the y direction, in which a first recessed part recessed in the y direction is provided in each curved pipe part of the first heat transfer pipe, and a part of each curved pipe part of the second heat transfer pipe is fitted into the first recessed part.

Abstract: A combustion device includes: a gas proportional valve; a control portion; a driving circuit; and a monitoring circuit. The monitoring circuit includes: a voltage generating portion configured to generate monitoring voltages corresponding to a driving current; and a branch output portion configured to output the monitoring voltages to a plurality of terminals of the control portion. When a voltage difference between the monitoring voltages input to the plurality of terminals is a determination reference value or more, the control portion determines that there is a failure of the monitoring circuit. When the voltage difference between the monitoring voltages is less than the determination reference value, and at least one of the monitoring voltages does not fall within a predetermined normal range while the gas proportional valve is controlled to become a predetermined state, the control portion determines that there is the failure of the monitoring circuit.

Abstract: In a communication system, a management server stores information about a hot water systems for each hot water system on the basis of individual identification information, and stores the individual identification information of a plurality of identification target machines for each hot water system. When the individual identification information of the plurality of identification target machines is received from a relay device, the management server collates the received individual identification information with the stored individual identification information.

Abstract: A heat exchanger includes: a casing into which heating gas is supplied; and a plurality of heat transfer tubes which are arranged in the casing, wherein the plurality of heat transfer tubes are set in a posture in which a plurality of straight tube portions are arranged in a direction intersecting a heating gas flow direction, are stacked a plurality of stages in the heating gas flow direction, and are distinguished into first and second heat transfer tubes respectively located on an upstream side and a downstream side in the heating gas flow direction, and wherein the second heat transfer tube is formed so that an outer diameter of the tube and an arrangement pitch of the plurality of straight tube portions are smaller than those of the first heat transfer tube.

Abstract: A hot-water supply system (1) remotely controls, via a server (50) and using a portable terminal device (30), a hot-water supply device (10) connectable to an external communication network (40). The hot-water supply system (1) is provided with a control unit which performs a notification process for notifying at least another, already-associated portable terminal device (30) that the portable terminal device (30) for performing remote control has been newly associated with the hot-water supply device (10). For example, a control unit of the server (50) performs the notification process as the control unit.

Abstract: A water heater (WH) comprises: a primary heat exchanger (H1) that recovers heat from heating gas; a secondary heat exchanger (H2); and a heating gas flow regulator (48, 40a) for regulating the flow of heating gas so that heating gas flowing inside a first case (2) of the primary heat exchanger (H1) in an area near at least one side wall part (20) of the first case (2) is prevented from entering designated gaps (C2, C3) in the secondary heat exchanger (H2). Thus, high temperatures in side wall parts (50) of the secondary heat exchanger (H2) can be suitably prevented and heating efficiency can be suitably improved.

Abstract: This method of manufacturing an outer case for a hot water unit involves a pressing step for subjecting a flat metal plate (30a) to press processing to form a component part (3) of the outer case (C), and a painting step for painting text, symbols, figures or patterns on the component part (3), wherein the painting step involves an inkjet printing step for forming an inkjet printing layer (4) by performing inkjet printing on the flat metal plate (30a). The pressing step is performed after the inkjet printing step, and after the pressing step, there is further a clear coating step for forming a clear layer (5) on the inkjet printing layer (4).

Abstract: A plate heat exchanger includes a plurality of plates stacked so that a liquid flow passage is formed on the inside thereof, and a gas flow passage through which heating gas passes, the gas flow passage being formed between the plurality of plates and including a gas inflow opening portion and a gas outflow opening portion positioned on an opposite side to the gas inflow opening portion, wherein the gas outflow opening portion has a smaller opening area than the gas inflow opening portion. Thus, when the heating gas passes through the gas flow passage, even if the volumetric flow thereof decreases due to a reduction in temperature or condensation, a reduction in the flow velocity of the heating gas can be suppressed. Hence, a reduction in a heat transfer coefficient can be suppressed, leading to an improvement in heat transfer efficiency, and as a result, reductions in overall size, weight, and manufacturing cost can be achieved appropriately.

Abstract: An air blowing fan supplies an amount of air corresponding to a fan rotation speed to a burner during operation. A check valve has a biasing force that closes an exhaust vent, and is opened and closed in accordance with a relationship between a gas pressure in an exhaust passage and the biasing force. A controller performs a failure diagnosis for detecting an open failure of the check valve when a phenomenon in which the gas pressure is lower than a predetermined normal pressure range is detected in a case where the fan rotation speed is within a predetermined diagnosis rotation speed region. The diagnosis rotation speed region is set within a rotation speed range in which a degree of opening of the check valve changes with an increase in the fan rotation speed when the check valve is normally opened and closed.

Abstract: A heat exchanger includes a tube expansion portion provided on a heat transfer tube such that an outer peripheral surface of the heat transfer tube is pressed against an inner peripheral surface of a first hole provided in a side wall portion of a case, and a first concave surface portion that is provided in a part of an outer surface of the tube expansion portion and forms a first gap, into which brazing material of a first brazed portion advances, between the outer surface of the tube expansion portion and the inner peripheral surface of the first hole. Thus, the attachment strength of the heat transfer tube can be improved by means of a simple configuration.

Abstract: This outer case (C) for a hot water unit, configured using a metal plate (30a), is provided with a paint layer (30b) which is provided to cover the front surface and/or back surface of the metal plate (30a), an inkjet printing layer (4) which is laminated on the paint layer (30b) and which shows text, symbols, figures and/or patterns, and a clear layer (5) which covers the inkjet printing layer (4). By means of this configuration, the outer case (C) can be produced with high productivity and at a low cost, and with excellent design and resistance properties.

Abstract: A hot water heating system is provided with: a hot water heating device; a heating terminal; a heat circulation circuit; a circulation means; and an expansion-absorbing means. The hot water heating device is provided with: a heating passage; a heating means for heating a heat medium inside the heating passage; a pressure detection means; a supply passage connected to the heating passage; an opening/closing means for the supply passage; and a control means which opens the opening/closing means to supply the heat medium when the internal pressure of the heating passage is less than a reference value. The control means determines that the positional relationship between the circulation means and the expansion-absorbing means is inappropriate when the pressure detected by the pressure detection means at the moment the circulation means starts to be driven is lower than the pressure detected prior to driving the circulation means.

Abstract: A heat exchanger including a gas inlet through which a combustion gas flows in and a gas outlet through which the combustion gas flows out is provided. The heat exchanger includes a housing in which the gas outlet is formed, a partition member, and a plurality of heat transfer tubes accommodated in the housing. The partition member is mounted in the housing so that there is a portion in which a flow area of the combustion gas is smaller than that of the gas inlet between the gas inlet and the gas outlet.

Abstract: There is provided a method of producing an exterior case for a hot water unit including a pressing process in which press processing is performed on a flat metal plate, and a component part of an exterior case used for accommodating a hot water device for hot water production or hot water storage therein is formed; and a painting process in which any of letters, symbols, figures, and patterns is painted on the component part of the exterior case, wherein the painting process includes an ink jet printing process in which ink jet printing is performed on the flat metal plate and an ink jet printing layer is formed, and wherein the pressing process is performed after the ink jet printing process.