Tech Tips
 Low Suction Pressure/High Superheat
FI0019

  • Unit Undercharged
  • Kinked Suction Line
  • Restricted Liquid Line
    • Kinked
    • Plugged Liquid Drier
  • Metering Device Restricted
    • Moisture Freezing at Metering Device
    • Clogged Metering Device
    • Incorrect Metering Device (undersized)
    • Bad TXV

Note: On systems with more than one TXV it is possible for one TXV to fail and the other to work. This will result in a Low Suction Pressure and High Superheat. Each TXV must be checked to determine which valve is functioning correctly.

    • Incorrect TXV Superheat Setting

Note: Smaller, five ton and less, TXV's generally have fixed superheat settings. Larger TXV's generally are field adjustable; however, superheat adjustments should only be performed by a technician that fully understands TXV's and superheat.