If a cap tube is partially clogged, what is an expected condition?

When a capillary tube is partially clogged, it restricts the flow of refrigerant through the system, leading to specific pressure conditions. In this scenario, the suction pressure is affected as the refrigerant cannot flow efficiently. Consequently, the suction pressure will be low, indicating that the evaporator is not receiving enough refrigerant to boil and absorb heat effectively.

At the same time, since the flow of refrigerant is limited, it can lead to higher than normal pressure building up downstream of the restriction, but if the head pressure is normal or low, that suggests the refrigerant in the high side of the system can still manage to condense adequately, albeit there may be some fluctuations depending on the system design and ambient conditions. Therefore, it’s critical to recognize that the suction side pressure dropping is a direct consequence of the restriction caused by the clogged cap tube.