Lincoln Aperion 24 Oven TC#1 / TC#2 Error: Thermocouple Disconnected
TC#1 Error, TC#2 Error, TC#1 and TC#2 Error, or Err in the set point field means one or both thermocouples are disconnected. Verify both are connected to the IO board and inspect the wires and connectors for cuts or disconnects. The alarm recovers automatically when the problem is removed.
High: the control has lost chamber temperature signals and the oven cannot hold heat properly.
- Code
- TC#1 Error / TC#2 Error / TC#1 and TC#2 Error (or Err in the set point field)
- Maker
- Lincoln
- Equipment
- Pizza ovens
- Applies to
- Aperion 24 UI
What does Lincoln error code TC#1 Error / TC#2 Error / TC#1 and TC#2 Error mean?
The Aperion 24 reads the baking chamber with two thermocouples, TC#1 and TC#2, wired to the IO board. If one or both are disconnected, the user interface shows an alarm: "TC#1 and TC#2 Error", "TC#1 Error", "TC#2 Error", or "Err" in the set point temperature field. The alarm names which thermocouple lost its signal, so it tells a technician which wire to follow. The manual gives one cause, one or two thermocouples disconnected. Its steps are to verify both thermocouples are connected to the IO board and to inspect the thermocouple wires and connectors for cuts or disconnects. The alarm recovers automatically when the problem is removed, so no reset is needed after the connection is restored. With one thermocouple missing, the control has less information about the chamber, and with both missing, it has none.
Affected models and control systems
The Lincoln Aperion 24 conveyor oven, model 2424E, an electric 60 Hz unit run from an easyTouch screen.
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
- TC#1 Error, TC#2 Error or TC#1 and TC#2 Error on the touchscreen
- Err in the set point temperature field
- Heating limited or stopped
Possible causes
Listed in Lincoln's documentation
- One or two thermocouples disconnected
Other likely causes — what usually sits behind error code TC#1 Error / TC#2 Error / TC#1 and TC#2 Error on this control. A technician confirms which one it is before any part is replaced.
- A thermocouple connector worked loose by vibration or heat cycling
- A thermocouple lead cut or pinched when the oven was serviced or cleaned
Safe checks before calling for service
- Note which message shows: TC#1, TC#2, or both.
- Turn the oven off and let it cool.
- Do not pull on wires or open panels.
- Tell the technician exactly which alarm text appeared.
How a technician diagnoses error code TC#1 Error / TC#2 Error / TC#1 and TC#2 Error
- Read the alarm text to see which thermocouple lost signal.
- Verify both thermocouples are seated on the IO board.
- Inspect the wires and connectors for cuts, pinching or loose pins.
- Measure thermocouple continuity.
- Replace the thermocouple or lead that fails.
- The IO board and thermocouple connectors are inside a heated oven with line voltage.
- Wires near the oven wall run hot.
- Thermocouple signals are tiny, so continuity needs careful testing.
How error code TC#1 Error / TC#2 Error / TC#1 and TC#2 Error differs from similar codes
Unlike SHORTED PROBE or OPEN PROBE on the Impinger II 1100, the Aperion names the thermocouple and recovers on its own once reconnected.
Technical reference
- Maker documentation
- Lincoln owner support
- Edition
- LIN_EO_SM_IMPAPERION2424_4607818 07/21
- Models / control
- Aperion 24 UI
- Section
- Section 5 Troubleshooting, UI Alarm Messages, pp. 28-29
- 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 Lincoln pizza oven error codes
Do I need to reset the alarm?
No, it recovers automatically when the problem is removed.
What does Err in the set point field mean?
It is one of the ways the display shows the thermocouple alarm.
Is TC#2 different from TC#1?
They are two thermocouples; the message says which one lost signal.
Need help with Lincoln error code TC#1 Error / TC#2 Error / TC#1 and TC#2 Error?
A technician confirms the cause on site and gives you the price in writing before any work starts.