What symptoms indicate a refrigerant overcharge in a capillary tube air conditioning system?

In a capillary tube air conditioning system, symptoms of a refrigerant overcharge primarily manifest in pressure readings. When an air conditioning system is overcharged with refrigerant, the excess refrigerant increases both the suction and discharge pressures. The high suction pressure indicates that the evaporator is flooded with refrigerant, preventing it from evaporating properly and absorbing heat. Simultaneously, the high discharge pressure indicates that the compressor is working harder than normal to pump the excess refrigerant, leading to potential strain and damage to the system.

The other symptoms listed in the options relate to different issues or conditions within an air conditioning system. For instance, a low suction pressure combined with low discharge pressure typically points to a refrigerant undercharge or an equipment malfunction. No airflow across the evaporator usually suggests a blockage or a fan failure, while water leakage from the system could indicate a refrigerant leak or a malfunction of the condensate system, not directly related to an overcharge condition. Therefore, the combination of high suction and discharge pressures is the most indicative of a refrigerant overcharge situation.