How to Solve Ice Blockage in Car Air Conditioning?
3 Answers
"The simplest method to address ice blockage in car air conditioning is to recharge the refrigerant. First, evacuate the refrigerant, then purge the system with nitrogen to remove air before adding the refrigerant back in, and replace the desiccant. One of the reasons for ice blockage in car air conditioning is the presence of moisture in the refrigeration system, where water freezes and causes the blockage. Ice blockage can only occur at the throttling points in the refrigeration system, specifically at the expansion valve's throttle orifice. Since refrigerant and water are generally immiscible, when the refrigerant flows through the small throttle orifice of the expansion valve, the temperature suddenly drops, causing any moisture mixed with the liquid refrigerant to freeze around the throttle orifice or valve needle hole. Another possible reason could be a malfunction in the air conditioning evaporator temperature sensor, preventing it from cutting off the compressor and stopping refrigeration when the temperature reaches a critical point. In such cases, you can check if the evaporator temperature sensor has failed or is disconnected, or adjust the critical temperature setting of the thermostat."
Had an annoying experience with AC icing while driving. In the middle of summer, the cold air suddenly stopped working. After checking, I found ice blockage in the pipes, most likely caused by moisture freezing in the system. I immediately turned off the AC and let the engine idle for a few minutes to melt the ice using engine heat. Then, I tried cleaning the filter and checking if the desiccant in the receiver-drier was saturated. If the problem persists, it's best to visit a repair shop to use a professional vacuum pump to remove moisture, replace the drier, or replenish the desiccant. Remember, during regular maintenance, have technicians check the system's sealing to prevent moisture ingress. Otherwise, frequent icing can damage the compressor, leading to costly and time-consuming repairs. I also learned not to turn off the AC immediately after parking—waiting about 30 seconds allows the system to dry out a bit, reducing the risk.
Having worked in automotive repair for many years, icing blockage is one of the common issues. The solution primarily relies on thorough dehumidification: first, use a vacuum pump to evacuate the entire air conditioning system, removing all moisture and air; then replace the dryer to ensure it can absorb residual moisture; if the icing blockage is caused by refrigerant leakage, also repair the leak and recharge the refrigerant. I recommend that car owners avoid disassembling it themselves, as using the wrong tools can easily damage the pipelines. For prevention, install a high-efficiency desiccant and perform routine vacuum checks every two years. Untreated icing blockage can reduce cooling efficiency and increase fuel consumption. Remember, professional handling takes only one or two hours and is safe and reliable.
