What are the symptoms of a clogged expansion valve?
2 Answers
When an expansion valve is clogged, symptoms such as poor cooling effect, frosting behind the valve, and abnormal compressor noise may occur. The expansion valve is a crucial component in the refrigeration system, typically installed between the liquid receiver and the evaporator. It allows medium-temperature, high-pressure liquid refrigerant to pass through its throttling mechanism, transforming it into low-temperature, low-pressure wet steam, which then absorbs heat in the evaporator to achieve the cooling effect. The expansion valve consists of three main parts: the valve body, the temperature sensing bulb, and the balance tube. Features of the expansion valve: 1. It employs an advanced double-flow balanced port structure; 2. The use of a double-flow thermal expansion valve reduces the number of expansion valves, check valves, and solenoid valves required in the refrigeration system; 3. The bidirectional balanced flow port allows the static superheat to vary with changes in the condensing pressure or the pressure drop across the valve port; 4. It maintains stable superheat, ensuring stable system operation; 5. It is suitable for various refrigeration and air conditioning applications.
When the expansion valve is clogged, the air conditioning cooling effect will significantly decrease, and the air coming from the vents will feel like room temperature, not cold at all; the compressor will frequently start and stop, creating noises such as humming or hissing sounds; sometimes, the pipes may frost over, leading to reduced airflow or even no airflow at all. Driving in hot weather becomes unbearable, with the cabin temperature soaring and affecting comfort, especially during long-distance trips. The system pressure also becomes unbalanced, with the high-pressure side abnormally rising while the low-pressure side drops too low, potentially causing refrigerant leaks or compressor overload damage. It is recommended not to delay repairs, as this can waste fuel and increase repair costs. Regular maintenance of air conditioning components can prevent such issues.
