Heat exchanger

A heat exchanger comprising:

• a case body;
• a plurality of heat-transfer pipes disposed in the case body;
• a connecting header configured to cover pipe ends of the plurality of heat-transfer pipes fixed on a side wall of the case body from outside the case body and connect the pipe ends of the plurality of heat-transfer pipes outside the side wall of the case body, the connecting header has a planar surface;
• an inlet pipe configured to supply a fluid to be heated into the heat-transfer pipes;
• an outlet pipe configured to lead out the fluid to be heated from the heat-transfer pipes;
• a temperature sensor configured to detect a temperature of a water passage, wherein the water passage is formed of the heat-transfer pipes, the connecting header, the inlet pipe, and the outlet pipe;
• and
• a sensor bracket configured to fix the temperature sensor to the sensor bracket, wherein
• the sensor bracket is joined and fixed to the connecting header,
• at least a part of a base portion of the sensor bracket forming a mounting surface of the temperature sensor is in surface contact with the planar surface provided in the connecting header, and
• the temperature sensor is secured to a joint portion of the base portion of the sensor bracket joined and fixed to the connecting header so as to detect the temperature of the water passage through the planar surface of the connecting header and the base portion of the sensor bracket.