Box Temperature Too High

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