Greenheck ERCH - Energy Recovery Unit with Packaged DX (468151) - Manual (Page 50)

50
Energy Recovery Unit with Packaged DX
Symptom Possible Cause Corrective Action
Liquid line
is too hot
Refrigerant undercharge . Adjust the charge by subcooling .
High discharge pressure . See “High discharge pressure” .
Liquid line is
frosted or wet
Restriction in liquid line . Clear restriction upstream of point of frosting .
Suction line
is frosting
Insufficient evaporator airflow .
Check airflow, check filters, check drive for
loose parts or belts .
Restriction in suction or liquid line . Restriction upstream of point of frosting .
Malfunctioning or defective expansion valve . Check bulb of thermal expansion valve .
Frost on evap coil
Hot gas bypass valve not functioning properly . Check valve . If defective, replace .
Manual hot gas bypass valve closed . Open valve .
Troubleshooting - General Refrigeration Circuit
Always have a completed Pre-Start-Up Checklist, unit Start-Up Checklist, and Optional Accessories Checklist prior to requesting parts or
service information.