Blodgett Convection Oven Error Code Prob: Probe Failure
Prob on a Blodgett Mark V oven with the IQ2T control means the control has detected a probe failure. The audible alarm sounds and Prob appears in the top display. The manual prints no operator step, so switch the oven off and have a technician check the probe.
High: without a reliable probe reading the control cannot regulate temperature, so the oven should stay off until it is checked.
- Code
- Prob
- Maker
- Blodgett
- Equipment
- Convection ovens
- Applies to
- Blodgett IQ2T control
What does Blodgett error code Prob mean?
The IQ2T control relies on one temperature probe to know what is happening inside the oven chamber. It reads that probe continuously, and every heating decision depends on the number it gets back. When the signal is missing or does not make sense, the control cannot trust any temperature value, so it posts Prob in the top display and sounds the audible alarm that accompanies every code on this control. The manual describes the code simply as a probe failure and gives no action for it. In practice that leaves the control unable to hold a setpoint, and an oven without a trustworthy reading is a poor candidate for unattended cooking. The display cannot separate a failed probe from a damaged connection on its way back to the control, so a technician measures both. Do not try to compensate by raising the setpoint.
Affected models and control systems
This applies to the Blodgett Mark V convection oven with the IQ2T control, taken from the Mark V Installation, Operation, Maintenance manual. Other controllers may not show Prob.
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
- Prob in the top display with an audible alarm
- The oven does not hold its setpoint, or heats unevenly
- Cook times drift because the displayed temperature is not reliable
- Heating may appear to stop or run without control
Possible causes
Likely causes — what usually sits behind error code Prob on this control. A technician confirms which one it is before any part is replaced.
- A broken or pinched probe lead between the chamber and the control, so the signal drops out
- Heat or moisture in the chamber has damaged the probe element after long service
- A loose probe connector at the control end that gives an intermittent reading
Safe checks before calling for service
- Switch the oven off and let it cool with the door closed.
- Look inside only when the chamber is cool; check that nothing has been pushed against or knocked loose from the probe.
- Power the oven on once and see whether Prob returns immediately or only after it starts heating.
- Write down whether Prob appeared at start-up or in the middle of a cook, and what the oven was doing, for the technician.
How a technician diagnoses error code Prob
- Read the code and note the oven model and the setting in use when Prob appeared.
- Measure probe resistance at the control end with the power off and compare it to the chart for that probe.
- Check the lead and connector for breaks, pinches and corrosion along the full run.
- Compare the probe against a reference thermometer in the warm chamber to see whether it tracks.
- Replace the probe or repair the lead only after the readings fail the test, then confirm the code stays clear.
- Testing the probe and its wiring requires access behind panels and a meter
- The same Prob display can come from the probe, the lead or the control input
- An unreliable temperature reading can let the oven overheat if it is used in the meantime
How error code Prob differs from similar codes
Prob means the probe signal itself is failing, whereas Hi means the chamber really is more than 40 F over setpoint; the two can appear together but they are checked differently.
Technical reference
- Maker documentation
- Blodgett owner support
- Edition
- PN 17561 Rev N (3/06)
- Models / control
- Blodgett IQ2T control
- Section
- Operation, Blodgett IQ2T Control, "Error Codes and Alarms" (manual page 23)
- 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 Blodgett convection oven error codes
Can I use the oven with Prob showing?
It is better not to. The control has lost a reliable temperature reading, so it cannot hold a setpoint or protect the oven from running hot.
Does Prob go away if I switch the oven off and on?
It might disappear briefly, but the manual gives no reset for it. If the probe is failing, Prob will come back when the oven heats.
Is Prob the same as HEAT ERR?
No. Prob is a probe failure. HEAT ERR is a slow heat-up warning, which can also happen with a healthy probe.
Need help with Blodgett error code Prob?
A technician confirms the cause on site and gives you the price in writing before any work starts.