Randell E03 Error Code
S3 Sensor Failure on the Danfoss controller
Source: Randell/8148n-290-pcb__rd-8000-290-9000w-290-spm.pdf
What does Randell E03 mean?
On a Randell prep table with the Danfoss controller, E03 is the S3 Sensor Failure alarm. S3 is one of the controller's temperature sensors (thermistors). E03 indicates the controller cannot read a valid value from S3 because the sensor has failed, gone out of range, or lost its connection, affecting the function that sensor monitors.
Symptoms
- Display shows E03 with the alarm LED lit
- Temperature control tied to the S3 sensor is affected
- Displayed temperature may be missing or incorrect
- Cooling or defrost behavior may be abnormal
Common causes
- Failed or out-of-range S3 thermistor
- Disconnected or loose S3 sensor connector at the controller
- Damaged sensor wiring
- Controller input fault
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Diagnostic steps
Confirm the alarm
Verify the Danfoss display reads E03, the S3 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 S3 sensor connection
Check that the S3 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 S3 thermistor.
When to call a professional
The Danfoss code table directs contacting service for an S3 sensor failure. Pinpointing the faulty thermistor and replacing it with the correct OEM part should be handled by a Randell Authorized Service Agent, since the manual requires factory-authorized service with OEM parts on these R290 units. Call service at 888-994-7636 if E03 does not clear after checking the connection.
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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
S1 Sensor Failure on the Danfoss controller
S2 Sensor Failure on the Danfoss controller