Probable Cause:
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.
Remedy:
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.