Abstract: A combustion plate is for use in a totally aerated combustion burner in which a plate main body made of ceramic has formed therein a multiplicity of flame holes for ejecting a premixed gas. The plate main body is provided, in a lattice shape, with non-flame-hole sections free of flame holes. Each of those sections of the plate main body which are enclosed by the non-flame-hole sections constitutes a collective flame-hole section having formed therein in a crowded manner a plurality of flame holes. Flame holes formed in those peripheral portions of the collective flame-hole sections which are adjacent to the non-flame-hole sections are smaller in diameter than the diameter of the flame holes formed in those portions of the collective flame-hole sections which are inner than the peripheral portions.

Abstract: A tubular burner includes: a mixing tube having an inlet port into which a fuel gas and primary air flow; and a flame hole member having a plurality of flame holes and being fitted into a front end portion of the mixing tube. The flame holes of the flame hole member are made up of a central main flame hole and a plurality of subsidiary flame holes positioned around, and each being smaller than, the central main flame hole. In an annular region of the flame hole member defined between an outer periphery of the flame hole member and the central main flame hole, a plurality of non-flame-hole regions which are free from formation of the subsidiary flame holes are provided at a circumferential distance from one another. The plurality of the subsidiary flame holes are formed in each of flame hole regions defined between the non-flame-hole regions.

Abstract: A solenoid valve has: a valve body; a moving core with a valve body on one end; a guide tube slidably enclosing the moving core; a stationary core disposed in an inner circumference of an opposite end portion of the guide tube so as to face an opposite end of the moving core; a valve spring to urge the moving core in a direction away from the stationary core; an electromagnetic coil disposed to enclose the guide tube; and a magnetic plate disposed on an opposite end of the guide tube having a caulked portion. The guide tube has a caulked portion formed to fix in position the stationary core by engagement of the caulked portion with a recessed groove formed on an outer periphery of the stationary core. When the stationary core is fixed in position by the caulked portion, that surface of the stationary core which faces the magnetic plate is either flush with, or is protruding beyond, the opposite end of the guide tube.

Abstract: A circulating-type hot-water supply device (1) is provided with a heat exchanger abnormality determining unit (62), which inhibits execution of a suitable temperature maintaining operation when the suitable temperature maintaining operation continued for a predetermined time or more and stops a circulating pump (25), and when a temperature rise range of a detected temperature of a heat exchanger outlet temperature sensor (2) after stopping the circulating pump (25) becomes equal to or more than a temperature rise threshold value determined according to a selected state of burner blocks (3a),(3b) in a combusted state immediately before stopping the circulating pump (25), determines that a heat exchanger is in an abnormal state.

Abstract: A flat burner has at an upper end thereof a rectangular flame port portion which has a straightening member with a plurality of straightening plates laterally disposed in parallel with one another. The straightening member has contact portions in which the straightening plates are brought into contact with one another at a plurality of longitudinal positions to thereby longitudinally segregate the flame port passages that are defined by each of the straightening plates. Out of the contact portions of the laterally inside straightening plates defining the laterally center-side flame port passages of the flame port portion, at least lower half of the contact portions that are positioned at least in predetermined longitudinal portions is formed into an inverse triangle as seen in the lateral direction.

Abstract: A flat burner has a mixing tube portion with an inlet port of a cross section elongated in a vertical direction and a throat portion lying adjacent to a back of the inlet port and having a cross section smaller than that of the inlet port. A distribution chamber portion introduces a mixture of a fuel gas ejected from a gas nozzle disposed to face the inlet port and primary air flowing from the inlet port. The throat portion is formed at a position in which a sectional center thereof is offset in one of the upward and downward directions relative to a sectional center of the inlet port. The gas nozzle is disposed such that an axis of the nozzle hole of the gas nozzle passes through a vertical position that is offset from the sectional center of the throat portion toward the sectional center of the inlet port.

Abstract: A hot water supply apparatus has: a thermo-sensitive valve which is connected in parallel to a cold water delivery pipe and a hot water delivery pipe and which is closed when the hot water temperature to flow inside the valve is above a predetermined temperature to thereby shut off communication between the cold water delivery pipe and the hot water delivery pipe; and a circulation pump. By operation of the circulation pump, water circulation takes place from a heat exchanger through the hot water delivery pipe, a return pipe, the circulation pump, and a cold water supply pipe back to the heat exchanger. When the thermo-sensitive valve is open, water circulation takes place also through the thermo-sensitive valve. Instantaneous hot water supply operation is finished when an amount detected by a flow sensor falls below a predetermined amount during the instantaneous hot water supply operation.

Abstract: A premixing apparatus for mixing a fuel gas with air has an air resistance changeover device for changing over a flow resistance in the air feed passage and a gas resistance changeover device for changing over a flow resistance in the gas feed passage. The air resistance changeover device includes a venturi portion provided in that part of the air feed passage which is on a downstream side of the butterfly valve. A gas chamber is provided in that part of the gas feed passage which is on a downstream side of the gas resistance changeover device. A gas suction portion is configured such that the fuel gas is sucked from the gas chamber into an entire circumference of that part of the air feed passage which is adjacent to a downstream side of the venturi portion.

Abstract: A combustion plate for use in a totally aerated combustion burner has a ceramic plate body with a multiplicity of flame holes formed therein for ejecting a premixed gas. The plate body is provided, in a lattice shape, with non-flame-hole portions having no flame holes therein. Each of such regions of the plate body as are enclosed by the non-flame-hole portions constitutes a collective flame-hole portion having formed therein a plurality of flame holes. It is so arranged that flame lifting can be effectively prevented in the flame holes on the periphery of the collective flame-hole portions. Along each of such sides of the non-flame-hole portions as are adjacent to each of the collective flame-hole portions, outside flame holes are formed at a predetermined spacing therebetween in a longitudinal direction of the non-flame-hole portions. This predetermined spacing is greater than a spacing, in the longitudinal direction of the non-flame-hole portion.

Abstract: A combustion apparatus has a burner, a combustion box containing therein a heat exchanger, an exhaust passage in fluid communication with the combustion box, a fan for supplying the burner with combustion air, and a predetermined length of air suction duct in fluid communication with a suction opening formed in a fan casing. The air suction duct has: on a downstream end thereof, an outlet cylindrical portion which is smaller in diameter than a diameter of the suction opening in the fan casing and which lies opposite to the suction opening; and a flange portion which overhangs radially outward from a perimeter of the air suction duct adjacent to the outlet cylindrical portion into contact with that peripheral portion of the fan casing which forms the suction opening. The flange portion is provided with an auxiliary suction opening in fluid communication with a space surrounding the outlet cylindrical portion.

Abstract: In a hot-water storage type heating unit 1, a liquid-liquid heat exchanger 15, which exchanges heat between a first hot-water circulation circuit 12 through which hot water stored in a hot-water storage tank 11 circulates and a heating circulation circuit 14 in which the hot water flows from a radiator unit 3 for heating, is disposed above the hot-water storage tank 11, and a circulation pump 16 is disposed in the first hot-water circulation circuit 12 on the downstream side of the liquid-liquid heat exchanger 15. In order to return the gas, which is separated by a gas-liquid separator 17 provided so as to be interposed 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, a return passage 18 which communicates between the hot-water storage tank 11 and the gas-liquid separator 17 is provided.

Abstract: A rich-lean burner with a lean flame port, a blind clearance, and a rich flame port has: a burner main body with a pair of burner-main-body side plates on both lateral sides thereof; a burner cap with a burner-cap side plate covering the burner main body from at least one lateral outside thereof; and a straightening member with straightening plates to divide the lean flame port into laterally disposed zones. Upper ends of the burner-main-body side plates are below upper ends of the burner-cap side plate and of the straightening plates. The straightening member has a partition plate which is located laterally outside an outer straightening plate contiguous to the blind clearance and which extends upward beyond the burner-main-body side plates. The blind clearance is defined between the partition plate and the outer straightening plate, and the rich flame port is defined between the partition plate and the burner-cap side plate.

Abstract: A tubular burner has a mixing tube which includes a rear-end inlet port into which a fuel gas and primary air flow, and a flame hole member having a plurality of flame holes and being fitted into a front end region of the mixing tube. The flame hole member is prevented from getting pulled out of position, without applying an undue force thereto. At a front end of the mixing tube a cylindrical elongated section is disposed in a manner to be elongated beyond a front face of the flame hole member. A convex portion is formed in the cylindrical elongated section so as to protrude diametrically inward of the cylindrical elongated section to prevent the flame hole member from getting pulled out of position in a forward direction.

Abstract: A room heater is controlled according to a difference between a detected temperature detected by a first room-temperature detector and a predetermined set temperature. When a detected temperature detected by a second room-temperature detector falls below a first reference temperature, the operation is started on receiving an on-command from a thermostat. When the detected temperature by the second room-temperature detector has raised above a second reference temperature which is set higher than the first reference temperature, the operation is stopped on receiving an off-command from the thermostat. The room heater is controlled to raise a set temperature by a predetermined value if it does not receive the off-command by passing of a first predetermined period of time after having received the on-command or if the detected temperature detected by the first room-temperature detector has been at the set temperature or higher without receiving the off-command for a second predetermined period of time.

Abstract: A room heater is operated on receiving an on-command from a thermostat when a detected temperature detected by a second room-temperature detector falls below a first reference temperature, and is stopped on receiving an off-command when the temperature detected by the second room-temperature detector is above a second reference temperature that is set higher than the first reference temperature or when the thermostat is manually operated to be switched off. A setting temperature for temperature control to be carried out when the on-command is received again is updated according to a difference between the set temperature and the temperature detected by the first room-temperature detector on receiving the off-command. When the off-command is received before passing a predetermined period of time after receiving the on-command, the updating of the set temperature is prohibited if the temperature detected by the first room-temperature detector is below a predetermined minimum lower reference temperature.

Abstract: When a detection temperature by a hot-water tank thermister (42) has been equal to or lower than a re-heating determination temperature over at least a re-heating determination time, a tank controller (50) performs a sterilization process by heating hot water within a hot-water tank (31) by means of a heat pump unit (60); and when the detection temperature by the hot-water tank thermister (42) has been equal to or lower than a determination temperature for prohibiting the use of stored hot water over at least a determination time for prohibiting the use of stored hot water, the tank controller (50) performs only a temperature regulation control via heating while keeping a hot-water flow regulation valve (34) in a closed state.

Abstract: A circulating-type hot-water supply device (1) is provided with a heat exchanger abnormality determining unit (62), which inhibits execution of a suitable temperature maintaining operation when the suitable temperature maintaining operation continued for a predetermined time or more and stops a circulating pump (25), and when a temperature rise range of a detected temperature of a heat exchanger outlet temperature sensor (2) after stopping the circulating pump (25) becomes equal to or more than a temperature rise threshold value determined according to a selected state of burner blocks (3a),(3b) in a combusted state immediately before stopping the circulating pump (25), determines that a heat exchanger is in an abnormal state.

Abstract: When a detection temperature by a hot-water tank thermister (42) has been equal to or lower than a re-heating determination temperature over at least a re-heating determination time, a tank controller (50) performs a sterilization process by heating hot water within a hot-water tank (30) by means of a heat pump unit (60); and when the detection temperature by the hot-water tank thermister (42) has been equal to or lower than a determination temperature for prohibiting the use of hot water in the hot-water tank over at least a determination time for prohibiting the use of hot water in the hot-water tank, the tank controller (50) performs only a temperature regulation control via heating while keeping a hot-water flow regulation valve (34) in a closed state.

Abstract: A tubular burner has: a mixing tube inclusive of an inlet port, a venturi section, and a tapered tube section; and a flame hole member having a plurality of flame holes and being adapted to be fitted into a front end region of the mixing tube. A flame hole member has a front plate and a rear plate, both of sheet metal make. The front plate has a first flame hole in the central portion of the front plate, and a plurality of second flame holes located around a periphery of the first flame hole. The rear plate has a first ventilation hole in the center thereof so as to lie opposite to the first flame hole, and a plurality of second ventilation holes of smaller diameter than the first ventilation hole.

Abstract: A combustion control system includes: a memory section having stored therein each control data corresponding to each of the models; a switch input section designating setting contents of each model, the setting contents being set for each of the setting items relating to the operation by switched-on/switched-off state of each switch; and an instruction section which instructs the combustion control based on control. The switch input section is provided with at least two groups each being made up of a plurality of switches. An abnormality distinguishing section is provided to distinguish whether on-off states of one group of switches and on-off states of the other group of switches coincide with each other. When the on-off states are distinguished not to coincide with each other, an instruction is given to stop the combustion control. Incomplete combustion is thus prevented even at the time of failure or wrong operation of switches.