With the development of modern society, people's pursuit of quality of life is also getting higher and higher. Traditional hot water equipment, gas water heaters, electric water heaters and solar water heaters can no longer meet people's hot water needs. Under such a form, air energy water heaters (heat pump water heaters), as the new fourth-generation water heaters, have begun to be regarded by more and more people as one of the must-have household appliances due to their advantages of energy saving, environmental protection, safety and comfort, and ease of use.