A residential split system had a compressor replaced last week; now the unit is not cooling properly. The evaporator seems starved of refrigerant. The liquid line is sweating where it leaves the dryer. This is most likely the result of:

A residential split system had a compressor replaced last week; now the unit is not cooling properly. The evaporator seems starved of refrigerant. The liquid line is sweating where it leaves the dryer. This is most likely the result of:

• A. Debris from the burned out compressor has clogged the dryer
• B. Low refrigerant charge
• C. Faulty thermostat
• D. Overcharged refrigerant

Answer: (A)

The situation points to contamination and flow restriction caused by debris from the recently replaced compressor. When a compressor fails, pieces of metal or worn material can circulate with the refrigerant. The filter-dryer is supposed to trap moisture and debris, but if debris clogs the dryer, refrigerant flow to the expansion device and evaporator is restricted. That restriction prevents enough refrigerant from reaching the evaporator, making it look starved and leading to poor cooling. The liquid line sweating after the dryer fits with a restricted path downstream of the condenser, where the refrigerant is being cooled and moisture condenses on the line. Other possibilities like a simple low charge, a faulty thermostat, or an overcharge don’t fit as well with the recent compressor work and the evidence of a clogged dryer.

The situation points to contamination and flow restriction caused by debris from the recently replaced compressor. When a compressor fails, pieces of metal or worn material can circulate with the refrigerant. The filter-dryer is supposed to trap moisture and debris, but if debris clogs the dryer, refrigerant flow to the expansion device and evaporator is restricted. That restriction prevents enough refrigerant from reaching the evaporator, making it look starved and leading to poor cooling. The liquid line sweating after the dryer fits with a restricted path downstream of the condenser, where the refrigerant is being cooled and moisture condenses on the line. Other possibilities like a simple low charge, a faulty thermostat, or an overcharge don’t fit as well with the recent compressor work and the evidence of a clogged dryer.