R-Pro › Field cases › Components
Subcooling Insufficient (<3°C) → Flash Gas in Liquid Line → TXV Hunting
Likely causes
Refrigerant shortage → insufficient refrigerant in condenser → subcooling below target
Check: Check liquid-line sight glass for bubbles + measure subcooling (target 5–8°C)
What to do: Leak check → repair leak → evacuate 30 min → recharge to spec
Excessive pressure drop in liquid line — oversized run or filter-drier clogged
Check: Measure filter-drier inlet/outlet temperature difference — >1°C indicates clogged
What to do: Replace filter-drier → evacuate then recharge
Receiver absent or undersized → low liquid level → unstable subcooling
Check: Check receiver sight glass for bubbles or liquid level below 1/4
What to do: Add refrigerant until sight glass clears and subcooling reaches 5–8°C
Field tip
Bubbles in sight glass confirm subcooling <3°C — always find the leak before adding refrigerant.
All 565 cases work offline in R-Pro, with error codes for 62 brands and P-T data for 108 refrigerants.
Open R-Pro →Related cases
- Liquid Refrigerant Entering Compressor (Flooded Start / Liquid Slugging)
- Compressor Motor Burnout / Ground Fault
- High Compressor Discharge Temperature (>107°C scroll, >120°C recip)
- Scroll Compressor Reverse Rotation — 3-Phase Miswiring
- Scroll Tip Seal Wear — Volumetric Efficiency Loss and Reduced Cooling Capacity
- Scroll Poppet Valve Fails to Close — Reverse Rotation Noise After Shutdown