| Questions | Cause | Remedy |
| What is the temperature control setting? | Control set too high | Reset control |
| Is the evaporator dirty or iced up? | Iced or plugged coil | Defrost or clean |
| Have you checked the refrigerant level? | Refrigerant shortage. Air in system | Repair leak and recharge |
| Have you checked the expansion valve? | Expansion valve Superheat set too high | Lower Superheat setting |
| | Expansion valve too small | Raise suction pressure with larger valve |
| | Plugged expansion valve or retainer | Clean or replace |
| Is system capacity sufficient for product load? | Product load greater than system capacity | Add additional units or replace |
| Is evaporator properly sized for product load? | Evaporator too small | Add evaporator surface or replace |
| Are refrigerant lines properly sized? | Refrigerant lines mis-sized | Replace with properly sized lines |
| Are there any restrictions? | Refrigerant lines restricted | Clear restriction |
