Hot water supply device

Abstract

A hot water supply device includes a heat exchanger, a temperature detection sensor detecting the surface temperature of the heat exchanger, and a fixing fitting fixing the sensor to a casing of the heat exchanger. The heat exchanger includes heat exchange tubing, a plurality of fins brazed to the heat exchange tubing, and the casing within which the tubing and the fins are housed, and to which both end portions of each of the fins are brazed. The fixing fitting includes a sensor fixing portion to which the temperature detection sensor is fixed, and fitting fixing portions attached to the casing. A predetermined gap is defined between the sensor fixing portion and the casing. The fitting fixing portions are brazed to an outer surface portion of the casing corresponding to the outside of a portion thereof where the casing and one or a plurality of the fins are brazed together.

1 . A hot water supply device comprising a burner unit, a heat exchanger for applying heat to water with combustion gases supplied from the burner unit, a temperature detection means for detecting a surface temperature of the heat exchanger, and a fixing fitting for fixing the temperature detection means on the heat exchanger, characterized in that:
 the burner unit includes a plurality of combustion tubes disposed in a predetermined arranging direction, with the plurality of combustion tubes including at least one usual combustion tube that is always performing combustion while hot water being supplied;   the heat exchanger comprises a heat exchange tubing through which hot water flows, a plurality of fins that are brazed to the heat exchange tubing, and a heat exchanger casing that houses the heat exchange tubing and the plurality of fins and to an inner surface of which both end portions of each of the plurality of fins are brazed;   the heat exchange tubing comprises a plurality of straight pipe portions that extend in the arranging direction and that are arranged so as to be spaced apart at predetermined intervals in a direction orthogonal to the arranging direction, connected together by a plurality of U-shaped link tubes;   the fixing fitting comprises a sensor fixing portion to which the temperature detection means is fixed, and a fitting fixing portion that are fixed to an outer surface of the heat exchanger casing; and   along with a predetermined gap being defined between the sensor fixing portion and the outer surface of the heat exchanger casing, the fitting fixing portion is brazed to the outer surface of the heat exchanger casing that corresponds to an exterior portion where the heat exchanger casing and one or a plurality of fins are brazed together.   
     
     
         2 . A hot water supply device according to  claim 1 , characterized in that:
 the heat exchange tubing comprises a lower heat exchange tubing that is disposed so as directly to oppose the burner unit from above, and an upper heat exchange tubing that is disposed above the lower heat exchange tubing and that applies heat to hot water heated by the lower heat exchange tubing; and   the fixing fitting is provided in a position on the outer surface of the heat exchanger casing so as to correspond to the most downstream side in the direction of hot water flow in the lower heat exchange tubing, and so as to correspond to the usual combustion tube.   
     
     
         3 . A hot water supply device according to  claim 1 , characterized in that the fixing fitting comprises a projecting lug that projects upward from an upper edge of the fitting fixing portion. 
     
     
         4 . A hot water supply device according to  claim 1 , characterized in that the fixing fitting comprises a pair of flanges that extend from both upper and lower edges of the sensor fixing portion, horizontally in a direction departing from the heat exchanger casing. 
     
     
         5 . A hot water supply device according to  claim 4 , characterized in that a protective cover that protects the sensor fixing portion and the temperature detection means is attached to the fixing fitting via the pair of flanges.