User Guide
USER GUIDE
 Troubleshooting 2
u-line.com
SAFETY • INSTALLATION & INTEGRATION • OPERATING INSTRUCTIONS • MAINTENANCE • SERVICE
ERROR NOTIFICATION
The 3000 model series continuously monitors a series of 
inputs and parameters to ensure proper and efficient 
operation of your unit. Should the system detect a fault, an 
error notification will be displayed on the user interface. 
See below for a list of errors.
NOTE: Single zone models will not use (L) left or (R) right 
zone indicators in error notification.
CHECKING PRODUCT TEMPERATURE
To check the actual product temperature in the 
unit:
1. Partially fill a plastic (nonbreakable) bottle with water. 
2. Insert an accurate thermometer. 
3. Tighten the bottle cap securely.
4. Place the bottle in the desired area for 24 hours. 
5. Avoid opening the unit during the testing period. 
Digital Display 
Functions, But 
Unit Does Not 
Cool.
Ensure the unit is not in “Showroom Mode.” 
Momentarily unplug or interrupt power 
supply to the unit.
Digital Display 
Shows an Error.
“Door” indicates the door may be opened 
too long. Ensure the door is closing 
properly. For other error codes contact 
U-Line Customer Service.
Product Is 
Freezing.
Because product in contact with the rear wall 
may freeze, ensure no product is touching 
the rear wall.
Adjust the temperature to a warmer set 
point.
Product Is Not 
Cold Enough.
Air temperature does not indicate product 
temperature. 
Adjust the temperature to a cooler set point.
Ensure unit is not located in excessive 
ambient temperatures or in direct sunlight.
Ensure the door is closing and sealing 
properly.
Ensure nothing is blocking the front grille, 
found at the bottom of the unit.
Ensure the condenser coil is clean and free 
of any dirt or lint build-up.
ID Description Solution
No Comm Unit lost 
communication to 
the display.
Disconnect and 
reconnect power to 
unit. Contact Customer 
Care if persistent.
(L) (R) Zone T 
Open
Left or right zone 
thermistor circuit 
open.
Contact Customer 
Care.
Amb Thrm Open Ambient thermistor 
circuit open.
Contact Customer 
Care.
(L) (R) Zone T 
Short
Left or right zone 
thermistor circuit 
shorted.
Contact Customer 
Care.
Amb Thrm Short Ambient thermistor 
circuit shorted.
Contact Customer 
Care.
Problem Possible Cause and Remedy
(L) (R) Temp Hi 
6H+
Left or right zone 
temperature +10° 
over set point for 
over 6 hours.
Verify door is closed 
and sealing. Contact 
Customer Care if 
persistent.
(L) (R) Temp Hi 
12H+
Left or right zone 
temperature +10° 
over set point for 
over 12 hours.
Verify door is closed 
and sealing. Contact 
Customer Care if 
persistent.
(L) (R) Temp Lo 
6H+
Left or right zone 
temperature -10° 
under set point for 
over 6 hours.
Verify door is closed 
and sealing. Contact 
Customer Care if 
persistent.
(L) (R) Temp Lo 
12H+
Left or right zone 
temperature -10° 
under set point for 
over 12 hours.
Verify door is closed 
and sealing. Contact 
Customer Care if 
persistent.
(L) (R) Door 
Open 5M
Left or right door 
switch open for 
more then 5 
minutes.
Verify door is closed 
and sealing. Contact 
Customer Care if 
persistent.
ID Description Solution










