The heater of an electric water heater is usually composed of a set of electric heating tubes, which are made of a metal material that can withstand high temperatures, such as stainless steel or copper. These electric heating tubes are installed inside the water heater, converting electrical energy into thermal energy through resistance, thereby heating the water. The power of the heater can usually be set at the factory or selected by the user according to their own needs when purchasing.

After the 1920s, there were not as many new applications and developments as in the previous period, but during this period, all kinds of electric heating appliances were redesigned and continuously improved, becoming a stage of improvement in the history of electric heating appliances. In terms of household electric heating appliances, various appliances are designed to be more beautiful, durable, and sturdy, and most of them have automatic temperature and time control.