In this work, we study an improved wood-burning stove with a water tank placed in the flue gas outlet for use as a heater. This system takes advantage of the waste heat of the gases that pass through the chimney to heat the water contained in the tank. The evaluations were carried out in a house located in the district of San Antonio de Chuca (Imata), province of Caylloma, department of Arequipa, Peru, located above 4500m above sea level, where temperatures decrease to -20 °C during winter. A method is proposed to measure the power input of the integrated tank, which consists of finding the maximum power that the flue gas delivers to the water in the tank when the stove is turned on. Once this power has been identified, the wood-burning stove is replaced by an electric heating system that delivers the same power to heat the water. Once the electrical system has been calibrated, the wate...