Central air conditioning auxiliary electric heater, also known as auxiliary electric heater or electric auxiliary, is a component of the central air conditioning water circulation system. When users use central air conditioning for heating in winter, the heating effect of the central air conditioning unit will be greatly reduced due to the low outdoor temperature. Relying solely on the working efficiency of the central air conditioning unit cannot meet the heating needs. In order to better meet the heating needs of users, auxiliary heaters need to be added to the central air conditioning unit. The auxiliary heater can be used independently or connected to the main unit. Connect the auxiliary heater to the air conditioning pipeline. During winter heating, the medium is heated by the auxiliary electric heater and enters the indoor terminal equipment to output heat. However, during summer operation of the air conditioning unit, the medium does not need to flow through the auxiliary heater and directly enters the indoor terminal equipment to output cooling capacity.