What is the primary symptom of a clogged cap tube in an air conditioning system?

The primary symptom of a clogged capillary tube in an air conditioning system is frost on the evaporator. A capillary tube is a type of metering device that regulates the flow of refrigerant into the evaporator coil. When the cap tube becomes clogged, it restricts the flow of refrigerant, preventing it from entering the evaporator coil properly.

As a result, the evaporator does not receive sufficient refrigerant to absorb heat effectively. This lack of proper refrigerant flow can cause the temperature of the evaporator coil to drop significantly, leading to moisture in the air around the coil freezing on its surface. This frost accumulation can eventually lead to a complete blockage of airflow, affecting the overall efficiency and function of the air conditioning system.

Recognizing the presence of frost on the evaporator can help technicians diagnose the issue of a clogged capillary tube, prompting them to investigate further, check for obstructions, and take appropriate corrective actions to restore normal refrigerant flow.