Randell E01 Error Code
S1 Sensor Failure on the Danfoss controller
Source: Randell/8148n-290-pcb__rd-8000-290-9000w-290-spm.pdf
What does Randell E01 mean?
On a Randell prep table with the Danfoss controller, E01 is the S1 Sensor Failure alarm. S1 is one of the controller's temperature sensors (thermistors) used to monitor the cabinet or coil. E01 indicates the controller cannot get a valid reading from S1 because the sensor has failed, gone out of range, or lost its connection.
Symptoms
- Display shows E01 with the alarm LED lit
- Temperature regulation tied to the S1 sensor is affected
- Displayed temperature may be missing or incorrect
- Compressor may not cycle normally
Common causes
- Failed or out-of-range S1 thermistor
- Disconnected or loose S1 sensor connector at the controller
- Damaged sensor wiring
- Controller input fault
Ask the AskWhiz AI about Randell E01
AskWhiz
online
Diagnostic steps
Confirm the alarm
Verify the Danfoss display reads E01, the S1 Sensor Failure alarm.
Disconnect power before inspecting
Ensure the unit is disconnected from its power source before checking the sensor or wiring, per the manual.
Inspect the S1 sensor connection
Check that the S1 thermistor is connected at the controller and that its wiring is not damaged or loose.
Verify cabinet temperature
Compare the displayed temperature against the set point to judge whether the unit is still holding safe temperature.
Contact service
The Danfoss table directs contacting service for a sensor failure; call 888-994-7636 to test or replace the S1 thermistor.
When to call a professional
The Danfoss code table directs contacting service for an S1 sensor failure. Sensor diagnosis and replacement with the correct OEM thermistor should be handled by a Randell Authorized Service Agent, since the manual requires factory-authorized service with OEM parts on these R290 units to avoid ignition risk. Call service at 888-994-7636 if E01 does not clear after checking the connection.
Stop searching through PDFs. Our AI assistant on WhatsApp is trained on official Randell documentation and can diagnose this fault code and guide you through the repair in minutes.
5 free questions per bot in your browser — no signup.
Other Randell Error Codes
Control probe alarm on the Carel controller (air/control temperature sensor)
Defrost probe alarm on the Carel controller (evaporator/defrost temperature sensor)
Open door alarm on the Carel controller
Low temperature alarm (Carel LO / Danfoss Lo)
High temperature alarm (Carel HI / Danfoss Hi)
Dirty condenser alarm on the Carel controller
Condenser Temperature High Limit alarm on the Danfoss controller
Line Voltage Too High alarm on the Danfoss controller
Line Voltage Too Low alarm on the Danfoss controller
Continuous Compressor Runtime alarm on the Danfoss controller
S2 Sensor Failure on the Danfoss controller
S3 Sensor Failure on the Danfoss controller