The multi gear classification type is a thermoelectric water heater that adjusts the heating power through multiple gear adjustments. It generally has 4-10 gears, 3 gears for small kitchen utensils, and 1 to 2 gears for hand washing utensils and electric faucets. Solar energy companion, also known as instant solar water heater (also known as instant hot water heater in the industry), does not require preheating, so instant hot water heaters do not generate heat loss during preheating. Additionally, as much water is used, the remaining water will not take away a lot of heat, resulting in waste, unlike storage water heaters. Experts have conducted specialized experiments. A 40L well insulated storage water heater requires no hot water 24 hours a day and consumes more than 1.2 kilowatt hours of electricity. The colder the weather, the higher the power consumption. Compared to this, the instant hot water heater is a national energy-saving product that saves water and electricity. It is a type of instant hot water device that cooperates with solar water heaters for auxiliary heating. It is suitable for use with solar, air, heating, electric and other water heaters as a hot water auxiliary device, and can be used for bathing, washing, or as a separate kitchen water heater. In solar energy, air energy, and other water heaters, when the temperature of the hot water cannot reach the desired temperature due to weather, season, water quality, and other reasons, the hot water heater is used for auxiliary heating, making the use of hot water more convenient and efficient, truly achieving energy conservation and emission reduction. Instant electric water heaters, also known as fast, fast, or instant water heaters, are characterized by the fact that when cold water exceeds hot water, as long as the outlet is opened, the energy source continuously supplies hot water within a few seconds. When hot water is not needed, the faucet can be turned off. A constant temperature instant heating electric water heater refers to an electric water heater that can maintain a water outlet temperature that is basically constant with the temperature set by the user despite changes in inlet flow rate, inlet temperature, and power supply voltage. Instant electric water heaters can save up to 30% -60% of electricity. The product is equipped with a heat recovery device and can be used with a 2.5 square millimeter power cord. The product is divided into two types: surface and concealed. It is suitable for large shower top sprays and is suitable for environments such as hotels, hotels, and homes. A family only needs 1 kilowatt hour of electricity to take a shower in a day. The structure of the water heater mainly includes three parts: heating cylinder, circuit board, casing, and accessories&Nbsp