SAFETY • INSTALLATION & INTEGRATION • OPERATING INSTRUCTIONS • MAINTENANCE •
SERVICE
Troubleshooting - Extended 1
USER GUIDE
u-line.com
FAULT SYSTEM DIAGNOSIS GUIDE
Error
Solution 1
Solution 2
Solution 3
No Comm
Inspect Customer UI and Data
Cable (if defective replace entire
door)
Zone T Open
Inspect zone thermistor
connection. Replace if
necessary.
Inspect main control wire
harness for splits or breaks.
Repair split or cut cabling.
Evap T Open
Inspect evaporator thermistor
connection. Replace if
necessary.
Inspect main control wire
harness for splits or breaks.
Repair split or cut cabling.
Amb Thrm Open
Inspect ambient thermistor
connection. Replace if
necessary.
Inspect main control wire
harness for splits or breaks.
Repair split or cut cabling.
Zone T Short
Inspect thermistor cable for
pinch points or damage.
Replace if necessary.
Inspect wire harness from main
control board for pinch points or
damage. Repair split or pinched
cabling.
Evap T Short
Inspect thermistor cable for
pinch points or damage.
Replace if necessary.
Inspect wire harness from main
control board for pinch points or
damage. Repair split or pinched
cabling.
Amb Thrm Short
Inspect thermistor cable for
pinch points or damage.
Replace if necessary.
Inspect wire harness from main
control board for pinch points or
damage. Repair split or pinched
cabling.
Temp Hi 6H+
If excessive frost is also noted,
inspect door and door gasket for
proper seal and alignment.
Inspect evaporator fan for
proper operation.
Inspect refrigeration system.
Reference the System Diagnosis
Guide.
Temp Hi 12H+
If excessive frost is also noted,
inspect door and door gasket for
proper seal and alignment.
Inspect evaporator fan for
proper operation.
Inspect refrigeration system.
Reference the System Diagnosis
Guide.
Temp Lo 6H+
Inspect main control for proper
relay operation.
Inspect refrigeration system.
Reference the System Diagnosis
Guide.
Temp Lo 12H+
Inspect main control for proper
relay operation.
Inspect refrigeration system.
Reference the System Diagnosis
Guide.
Door Open 5M
Verify door closes properly.
Inspect cable arm, verify
presence of magnet, verify
proper
operation
and
movement or arm.
Inspect reed switch wiring.
THERMISTORS
Thermistors are used for various temperature
readings. Thermistors provide reliable temperature
readings using a resistance which varies based on
surrounding temperatures. If a faulty thermistor is
suspected it may be tested using an accurate
ohmmeter. In an ice water bath (32°F) resistance
should measure 16.1 kilohms.
5K OHMS @ 77°
16.1K OHMS - 32°F ambient
THERMISTOR FAILURE
Limp Mode Data Table
Mode
ON
OFF
Beverage/Drinks
10 min.
45 min.
