Abstract: Due to its small volume ,it is easy to be short of water in the process of using kitchen water heater. In order to provide as much hot water as possible without changing the volume, by recording the actual water temperature change of the tank of the water heater during the heating process, and the rise of the actual water temperature of the tank after the power failure. It is found that there is a big difference between the water temperature of the cupboard container and the set temperature, and the water temperature of the cupboard container will rise for a period of time after the heating stops. Finally, the improvement plan is provided according to the actual situation after analysis.

Key words: Uniformity, Temperature rise of waste heat, Water temperature