A certain degree of refrigerant leakage occurs in the air conditioning system pipeline or the indoor unit fan motor is abnormal.
When the refrigerant in the air conditioning system pipeline leaks to a certain extent, the suction temperature of the air conditioning compressor will increase, the exhaust temperature will increase, and the refrigerant flow rate in the evaporator is insufficient, resulting in a rapid drop in the coil temperature of the heat exchanger after the indoor fan motor is turned on. When the coil temperature drops to the anti-cold air protection temperature value set by the air conditioning program, the indoor fan stops running. Before the indoor fan motor stops running, the air outlet temperature of the air conditioner indoor unit changes from high to low, which feels hot and cold for a while.
When the indoor fan motor or motor capacitance is abnormal and the indoor unit air volume is small, the heat of the indoor unit heat exchanger cannot be effectively brought into the room, and the air conditioner compressor will be shut down during operation under high exhaust pressure protection or overload protection. Hot air is blown when the compressor is running, and the air blown out when the air conditioner protection stops the compressor is cold air.
In the event of such abnormal operation, it is recommended to directly report to the air conditioning manufacturer for after-sales repair, and the maintenance personnel will repair and troubleshoot the problem on site.