Tech Tips

Low Suction Pressure/ 
Low Superheat

Fixed Metering Device
FI0135

• Low Airflow
• undersized duct, return and/or supply
• improperly installed duct, return and/or supply
• dirty air filter
• air filter with excessive resistance to air flow
• closed or blocked supply or return registers
• more than one filter installed
• bad blower motor and/or capacitor
• incorrect blower motor
• blower wheel not turning proper direction
• loose blower belt
• incorrect sheave adjustment
• incorrect drive package for application

• Low Load
• low return air temperature
• dirty or matted indoor coil
• recirculation of supply air into return air
• Bad Indoor Blower Motor and/or Motor Capacitor
• Incorrect Blower Motor, Motor Capacitor, or Blower Wheel
• Unit Operating in Low Ambient Conditions Without Low Ambient Controls