40
PROBLEM
POSSIBLE CAUSE
CORRECTION PROCEDURE
Suction pressure too low
Discharge pressure is low
See Discharge Pressure Too Low section of this table above.
Low thermal load
Check building load.
Low refrigerant
Check for and repair leaks and add refrigerant as necessary.
Low airflow in evaporator
Clean filter.
Remove scale.
Check for blockage in ducts.
Check fan rotation.
Check motor operation.
Check belts.
Low refrigerant flow in evaporator
Check for obstruction in filter drier.
Check for obstruction in TXV.
Check super heating.
Check position of TXV bulb and equalizer.
Suction pressure too high
High thermal load
Check design conditions.
Compressor defect
Check pressures, and replace if necessary.
Condensate water leaks
Defective connection
Check and correct.
Blocked drain
Clean drain pan.
Drain lines incorrect
Check and correct.
LEGEND
TXV
—
Thermostatic Expansion Valve
Table 14 — Troubleshooting Procedure (cont)
