Thermador Oven Error Code Fb

The Fb code means the main relay board has detected a communication error with the display head. The relay board and the display panel have lost the ability to exchange data signals properly. This typically points to a loose wiring connection, a damaged harness, or a failed display head.

When the Fb error is active, the oven is not operating normally because the relay board and display head cannot communicate. You should not attempt to use the oven until the fault is diagnosed and repaired. Continuing to operate the oven with an unresolved communication fault could lead to unpredictable behavior.

Repair costs vary depending on the root cause. If the fix is simply reseating a loose connector, you may only pay for a service call, typically in the range of $75 to $150. If the display head needs to be replaced, parts and labor combined can range from $200 to $500 or more depending on your model and location. Relay board replacement tends to fall in a similar or higher cost range.

Some causes of the Fb error are DIY-accessible, such as inspecting and reseating loose wiring connectors at the relay board and display head. However, if the display head or relay board has actually failed, replacing those components involves working inside the oven's electrical system and is best handled by a qualified technician. Always disconnect power to the oven before inspecting any internal connections.

Resetting the oven by cutting power at the breaker for a few minutes may temporarily clear the Fb code if the fault was caused by a momentary communication glitch. However, if the underlying issue is a damaged harness, loose connector, or failed display head, the code will return once power is restored. A reset is a reasonable first step but is not a substitute for a proper diagnosis.