U-Line Bar Refrigerator Error Codes E1 to E4: Open Thermistor
E1 to E4 on a U-Line Class series bar refrigerator mean thermistor 1 to 4 is open. E4 does not apply to some models. The errors are logged in memory, so check the thermistor status in service mode and replace the thermistor if the error repeats.
Medium: a temperature sensor is open, so the control may not regulate properly.
- Code
- E1-E4 (Class/1000/2000 beverage)
- Maker
- U-Line
- Equipment
- Bar refrigeration
- Applies to
- U-Line Class, 1000, 2000 beverage centers
What does U-Line error code E1-E4 mean?
Thermistors are the temperature sensors in the cabinet. The control reads each one, and if a thermistor circuit is open, it records the matching error: E1 for thermistor 1, E2 for thermistor 2, E3 for thermistor 3, and E4 for thermistor 4. E4 does not apply to some models, because they have fewer sensors. Within this family the numbers E1 to E4 mean open thermistors, not a door event, and E5 to E8 mean the shorted equivalents. Only the door error is shown on the display; these are logged in memory. A technician opens service mode, reads the thermistor status and, if the error repeats, replaces the thermistor. An open sensor means the control cannot see the real temperature, so cooling can run wrong. Depending on which thermistor is lost, the unit may run too long and over-cool, or cycle too little and let the cabinet warm, so the usual sign a person notices is drinks at the wrong temperature rather than any message.
Affected models and control systems
U-Line Class series U-1215BEVS-00A and U-1224BEVS-00A. The 1000 and 2000 beverage platforms were not covered, so this page is for the Class series.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- Cabinet too warm or too cold
- Compressor running continuously or not at all
- Entries in the service-mode error log
Possible causes
Likely causes — what usually sits behind error code E1-E4 on this control. A technician confirms which one it is before any part is replaced.
- Thermistor 1, 2, 3 or 4 circuit open
- Thermistor wire pulled loose at the connector
- Thermistor damaged by moisture
- Connector at the control board corroded
Safe checks before calling for service
- Check that the door closes and the unit is level.
- Note any temperature drift in the cabinet.
- Do not unplug sensors.
- Write down which of E1 to E4 the technician should look for and the model.
How a technician diagnoses error code E1-E4
- Open service mode and check thermistor status.
- Identify which thermistor reads open.
- Measure its resistance and check the connector.
- Repair the connector or replace the thermistor.
- Run the unit and confirm the reading and cabinet temperature are sensible.
- Sensor testing happens inside service mode and at the control board.
- Resistance measurements need a meter and the maker's values.
How error code E1-E4 differs from similar codes
E1 to E4 are open thermistors and E5 to E8 are shorted ones; E0 and E9 on the same control are door errors.
Technical reference
- Maker documentation
- U-Line owner support
- Edition
- Publication Number 30379, 3/2024 Rev. Q
- Models / control
- U-Line Class, 1000, 2000 beverage centers
- Section
- Troubleshooting / Control Operation - Service
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related U-Line bar refrigeration error codes
Which thermistor is which?
E1 is thermistor 1, E2 is 2, E3 is 3 and E4 is 4.
Why is nothing shown on the display?
Only door errors are shown. These errors are logged in memory.
Does E4 apply to my unit?
Only to models with four sensors. The 1215BEV has fewer, so E4 does not apply there, while the 1224 series can carry it.
Need help with U-Line error code E1-E4?
A technician confirms the cause on site and gives you the price in writing before any work starts.