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Error code reference

Thermador Range Error Code F143

Vcc open circuit on slave micro.

Thermador codesThermador range codes
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What the F143 error code actually means

The F143 code means your range's control system has lost an important power connection to one of its internal circuit boards, preventing it from communicating properly. This is usually caused by a loose wire connection or a failed electronic board inside the range. The range will need a technician to inspect the wiring and potentially replace one of the control boards to restore normal operation.

Diagnostic procedure

The full F143 procedure

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1
First diagnostic step
Check power display and Display Board connectors P1B and associated wiring. If OK, replace Power Board. If fault persists, replace Display Board.
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Most common causes of F143

Ranked by how often they cause this code
  1. 1Loose or faulty connector P1B
  2. 2Damaged wiring harness
  3. 3Failed Power Board
  4. 4Failed Display Board

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Questions people ask about F143

What does F143 mean on a Thermador range?
F143 indicates an open circuit on the Vcc power supply line feeding the slave microcontroller on the Display Board. This means the secondary processor is not receiving the voltage it needs to operate. The fault is traced through connector P1B, the associated wiring harness, the Power Board, and the Display Board in that order.
Is it safe to use my Thermador range while F143 is displayed?
It is not advisable to continue operating the range while F143 is active. The fault indicates a failure in the control board communication circuit, which means the control system may not be functioning reliably. Attempting to use the range in this state could result in unpredictable behavior from the controls.
How much does it cost to repair a Thermador range F143 error?
Repair costs depend on what component is at fault. If the issue is a loose connector or damaged wire, the cost may be limited to a service call fee, typically in the range of $75 to $150. If a Power Board or Display Board replacement is needed, parts alone can range from $150 to $400 or more depending on the model, with additional labor costs on top of that.
Can I fix F143 on my Thermador range myself?
A knowledgeable DIYer can start by inspecting connector P1B and the wiring harness between the Power Board and Display Board for obvious damage or loose connections. However, if the boards need to be tested for voltage output or replaced, working with live appliance electronics carries real risk, and a qualified technician is recommended for board-level diagnosis and replacement.
Will resetting my Thermador range clear the F143 error?
A power reset, such as unplugging the range or switching off the circuit breaker for a few minutes, may temporarily clear the display, but F143 will return if the underlying open circuit condition is still present. The fault needs to be diagnosed and the hardware issue resolved for a permanent fix.

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