Pin and seat of expansion valve wire drawn, eroded, or held open by foreign material- resulting in liquid floodback. Moisture freezing valve pin in open position. If suspected, inspect AMI moisture indicator for moisture contamination reading.
Clean or replace damaged parts or entire valve. Install an ALCO EK Plus and STAS filter-drier
Apply heat gun to the valve to melt the ice.
Install an EK-Plus or STAS filter-drier to insure a moisture- free system.