| Questions |
Cause |
Remedy |
| Is the evaporator coil clean? |
Dirty or iced evaporator |
Clean or defrost evaporator |
| Have you checked refrigerant charge? |
Refrigerant shortage. |
Repair leak & recharge. |
| Where is unit located? What is air temperature entering condenser? |
Condensing temperature too low |
Replace or repair existing condenser control. Add if none exists |
| Are suction lines insulated properly? i.e. from outside of box to compressor. (Cold weather) |
Suction lines improperly or not insulated |
Insulate suction lines |
| Do you have the correct expansion valve? |
Undersized expansion valve |
Replace with properly sized expansion valve |
| Is expansion valve in proper adjustment? Is superheat correct? |
Expansion valve underfeeding |
Adjust expansion valve until proper superheat is reached |
| Do you have a pressure drop across filter drier? |
Clogged filter drier |
Replace core(s) or entire suction filter |
| Do you have a pressure drop across suction filter? |
Clogged suction filter |
Replace core(s) or entire suction filter |
| Are suction lines restricted? |
Restricted suction lines |
Remove restrictions or replace |
