The temperature controller is a very important safety component of an electric water heater. It can monitor the water temperature of the water heater through a temperature sensor and maintain the water temperature within a set range by controlling the switch of the heater. If the water temperature reaches the set maximum temperature, the temperature controller will automatically turn off the heater to prevent danger caused by excessive water temperature.

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.