Home warm water showers are designed according to the principle of air suction when liquid flows in pipes. Its main component is the mixing valve. When the high-speed liquid flows through the mixing valve, due to the sudden reduction of the pipe diameter and the increase of the liquid flow rate, the pressure on the pipe wall suddenly decreases, and a negative pressure is formed at the branch of the mixing valve. The negative pressure can suck the liquid in the branch pipe. Therefore, in use, as long as one end of the mixing valve is connected to the tap, the hot water pipe is inserted into the kettle, and the tap is turned on, the hot water will be inhaled and mixed with cold water into warm water.