Southbend Commercial Oven Error Code F3: Open Temperature Probe
F3 on a Southbend convection oven means the temperature probe is open. The manual says to check the connection, and if it is fine, to replace the probe. Turn the oven off and let it cool before anyone checks it.
High: with no probe reading, the oven cannot regulate its temperature.
- Code
- F3
- Maker
- Southbend
- Equipment
- Convection ovens
- Applies to
- Gas and Electric SilverStar / Marathoner Gold convection control (programmable and rack-timer models)
What does Southbend error code F3 mean?
The probe sends the cavity temperature to the controller, usually as a resistance that changes with heat. An open probe means the circuit is broken, so the controller receives no reading. When it sees that, it shows F3. The manual's remedy is short: check the connection, and if the connection is fine, replace the probe. The reasoning is practical. An open circuit is often a plug that has come loose or a wire that has broken at a bend, and these are cheap to find before replacing the probe. A controller with no temperature reading cannot safely run the heat, so the oven stops instead of guessing. Opposite to F4, where the probe circuit is shorted, F3 means the circuit has no continuity at all.
Affected models and control systems
Southbend Marathoner Gold and SilverStar gas convection ovens, programmable and rack-timer models (GB/15PC, SLGB/15SC), and Southbend electric convection ovens EB/10PC, programmable and rack-timer models.
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
- F3 appears on the control display
- The oven stops heating or will not start heating
- The temperature display shows nothing sensible
- F3 returns each time the oven starts
Possible causes
Likely causes — what usually sits behind error code F3 on this control. A technician confirms which one it is before any part is replaced.
- Open temperature probe
- A probe connector that has loosened from vibration and heat cycling
- A probe lead broken where it bends inside the cavity wall
Safe checks before calling for service
- Turn the oven off and let it cool completely.
- Look at the probe inside the cavity, if you can see it, for obvious damage, without bending it.
- Turn the oven back on once.
- If F3 returns, write down the model and call us without opening the panel.
How a technician diagnoses error code F3
- Read the code and confirm it is F3 on this model.
- Check the probe connection at the controller and at the probe.
- Measure the probe resistance and look for an open reading.
- Inspect the probe lead for a break.
- Compare the resistance with the expected values.
- Replace the probe if the connection is fine.
- The probe lead runs through the oven wall near heat and wiring.
- A resistance test needs the probe disconnected and the oven powered down.
- The probe has to be positioned correctly after replacement.
How error code F3 differs from similar codes
F3 is an open probe circuit, and F4 is a shorted probe circuit. F1, F5, F6 and F8 are controller codes.
Technical reference
- Maker documentation
- Southbend owner support
- Edition
- Part No. 1181887, Rev. 1
- Models / control
- Gas and Electric SilverStar / Marathoner Gold convection control (programmable and rack-timer models)
- Section
- Troubleshooting, Interpreting displayed error codes (manual p. 42)
- 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 Southbend convection oven error codes
Does F3 mean the oven is broken?
It means the probe circuit is open, which is often a connection or the probe itself.
Can I cook without the probe?
No. The controller needs the probe to regulate temperature.
Is it the controller?
The manual says to check the connection and then replace the probe, not the controller.
Need help with Southbend error code F3?
A technician confirms the cause on site and gives you the price in writing before any work starts.