Heat exchanger having circulation guide

A heat exchanger including a circulation guide, the heat exchanger comprising:

• a heat exchanger body including therein a water chamber;
• a top body tube including therein a fire chamber, installed at a top end of an inside of the heat exchanger body, and including a sidewall of which at least a portion is spaced apart from an inner circumferential surface of the heat exchanger body;
• an inlet port formed at a bottom end of the heat exchanger body and allowing water to be supplied therethrough to the water chamber;
• an outlet port connected to a top end of the heat exchanger body and allowing the water that is heated while passing through the water chamber to be discharged therethrough;
• a spiral guide formed at the sidewall of the top body tube in a spiral direction and guiding the water having passed through the water chamber to be discharged to the outlet port without stagnation;
• and
• a plate-shaped guide including a peripheral side flow guide penetrated and supported by at least some of a plurality of combustion pipes, blocking a portion of the water chamber of the heat exchanger body to change flow of the water forcibly, and spaced apart from a floor surface of the top body tube by a distance in a range of 15 mm to 20 mm.