Delfield Prep Table Error Code E03: Sensor 3 Defect
E03 on a Delfield NP prep table means the control reports a defect in sensor 3. The manual's comments column for this row reads Open and does not name which sensor it is.
Medium: a temperature input has failed and its role is not named, so a technician has to confirm what it affects.
- Code
- E03
- Maker
- Delfield
- Equipment
- Prep tables
- Applies to
- 4400/4500 Series NP refrigerated prep tables with R290 temperature control (4424NP-4472NP, D4424NP-D4472NP, ST4424NP-ST4472NP and variants)
What does Delfield error code E03 mean?
The R290 control of a Delfield NP prep table has several temperature inputs. When one of them returns a bad reading, the control replaces the box temperature on the display with a code that identifies the input. E03 is the code for sensor 3. The manual's table says sensor 3 defect, and the comments column simply reads Open. It does not say which sensor that is, where it sits, or what the control does when it cannot read it. In the context of a temperature sensor the word Open normally describes a circuit that has no continuity, but the manual does not spell that out, so we treat it only as the table's own label. No causes are listed beyond the sensor failing and no steps are given for the operator. The honest summary is that E03 tells you an input has failed and that a technician must find out which sensor it is on your specific table.
Affected models and control systems
The manual covers the 4400 and 4500 Series NP refrigerated prep tables with the R290 temperature control, including the 4424NP to 4472NP, D4424NP to D4472NP and ST4424NP to ST4472NP sizes and their variants.
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
- E03 on the display
- Normal temperature reading not shown
- Unit still running with no obvious change
Possible causes
Listed in Delfield's documentation
- Sensor 3 reported defective, with the manual's comments column showing Open
Other likely causes — what usually sits behind error code E03 on this control. A technician confirms which one it is before any part is replaced.
- Sensor lead broken or pulled out of its connector
- Connector corrosion from wash-down moisture
- Optional sensor input on that table that is damaged or no longer connected
Safe checks before calling for service
- Check the food temperature with a separate thermometer.
- Note whether E03 stays on steadily or comes and goes.
- Do not open the control housing. The manual gives no operator action.
- Check that no one has pulled on a sensor cable at the back or side of the unit.
- For the service call, write down E03, the unit model and size, and your own temperature reading.
How a technician diagnoses error code E03
- Read E03 and any other codes, then identify which sensor input is sensor 3 on that specific model.
- Trace the sensor cable and connector for breaks or loose pins.
- Measure the circuit with a meter: an open circuit will show no continuity.
- Confirm the control with a substitute sensor before replacing the board.
- Verify the display returns to a temperature after the repair.
- The control housing and connectors are tested with power disconnected and a meter.
- The manual does not name sensor 3, so a technician has to identify it from the wiring of the specific table.
- Replacing the board without proving the sensor first can leave the same code showing.
How error code E03 differs from similar codes
Unlike E01 and E02, the manual does not name sensor 3. E04 is the next sensor code, also marked Open and not named.
Technical reference
- Document
- Prep Tables & Compact Refrigerators, 4400 & 4500 Series: Specifications, Installation, Operation & Maintenance Manual
- Edition
- Part Number 9295093A, 11/25 (page footers 10/25)
- Models / control
- 4400/4500 Series NP refrigerated prep tables with R290 temperature control (4424NP-4472NP, D4424NP-D4472NP, ST4424NP-ST4472NP and variants)
- Section
- Section 3 Operation, 'R290 Temperature Control & Display' table, p. 23-24
- 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 Delfield prep table error codes
Which sensor is sensor 3?
The manual does not say. Its comments column for E03 reads Open.
Can I reset E03?
The manual gives no reset for it. It lists the indication only.
Is it the same as E04?
No. They are separate inputs, sensor 3 and sensor 4, though the manual treats them the same way.
Need help with Delfield error code E03?
A technician confirms the cause on site and gives you the price in writing before any work starts.