Thermador Wall Oven F- in the Legacy SC/SM Family: Main Board Communication Error

What F- means

A flashing F- on an older Thermador SC, SCD, SM or SMW oven means the main power/relay board has detected a communication error. In the service document the control head is named as the cause, along with the power and communication connections between both power/relay boards and the head. It is the board-side twin of FC.

Usual causes of F-

Control head
Power or communication connection between the two power/relay boards and the control head

✓ A safe check worth trying

1. Cut the oven's power with OFF or the breaker. 2. Wait 3 minutes and power it up again. 3. If F- stays on the display, write it down with the model number. 4. Do not disconnect any cable. Call us.

! Why you should stop here

Communication cables carry live signals and fit tightly
The control head is replaced only after the connections test good
The code reads like others, so exact display matters

Taking off a panel yourself does not by default void a manufacturer warranty, yet it can lead to accidental damage, and some manufacturers attach their own service terms. Read your warranty paperwork, or ask us, before you decide.

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More Oven codes

F24Thermador C-Series Oven F24 (F-24 in Manuals): Touch Key Stuck or Panel Blocked F63Older C/CM-Series Thermador Wall Oven F63: Wrong Lower Oven Temperature FCOlder SC/SM-Series Thermador Wall Oven FC: Display Head Communication Error F25Thermador Legacy C/CM/CJ Oven Displays F25: Several Touch Keys Stuck at Once F64F64 on an Older Thermador Wall Oven (C/CM-Series): Lower Cooling Fan Air Switch Not Detected FFFF on an Older Thermador Wall Oven (SC, SCD, SM, SMW): Bad Analog/Digital Converter F30Thermador C-Series Upper Oven, Sensor Shorted: F30 on C271 to CJ302 Models F70Thermador Wall Oven F70 in the Legacy C/CM Family: Lower Meat Probe Shorted

F-F- questions

How does F- differ from FC?

FC is a communication error seen by the display head. F- is one seen by the main power/relay board. Both involve the same link, viewed from different ends.

Is the dash part of the code?

Yes. The Care & Use manual lists F- on its own alongside Fr, FC and FF. When you call, say exactly what the display shows.

Is a reset worth trying?

Yes, once. It can clear a one-time communication glitch. If F- returns, the link needs testing by a technician. For an older oven we begin with the model number on the frame.