Thermador Cooktop Error F5: Temperature Sensor Fault or Safety Timeout

1. SAFETY: If the zone switched off unexpectedly, do not touch the cooking surface — it may still be hot.
2. First determine which F5 variant applies: if the zone was running for an extended period unattended, it is likely a safety timeout.
3. For safety timeout: turn the zone control to the off position, then back to your desired setting — this resets the timeout.
4. For a sensor fault: disconnect power at the circuit breaker for 30 seconds, then restore.
5. If F5 returns immediately on the same zone with no extended runtime, the sensor has failed — do not use that zone.
6. Call Thermador Customer Support at 1-800-944-2904 for a sensor fault.

Error F5 on your Thermador cooktop means: F5 covers two distinct conditions: (1) a temperature sensor has a short-circuit fault — the sensor is reading incorrectly, or (2) a cooking zone has automatically switched off after approximately 2 hours of continuous use as a safety measure. The appliance's self-diagnostic system has flagged this condition and may have disabled the affected zone or function to prevent damage or unsafe operation.

The most frequent cause is zone safety timeout — the zone ran continuously for approximately 2 hours without any control input (automatic bosch safety shutoff). Work through the causes and fix steps below in order — starting with the simplest check.

Some cases of F5 can be partially addressed by the homeowner. The steps below cover the DIY checks — if they do not resolve the condition, a technician is needed.

A faulty temperature sensor means the appliance cannot accurately measure heat — it may overheat (if the sensor reads low) or refuse to heat at all (if the sensor reads high or open). Running the appliance with a failed sensor risks damaging heating elements, food, or the appliance itself.

• Zone safety timeout — the zone ran continuously for approximately 2 hours without any control input (automatic Thermador safety shutoff)
• Short-circuit fault in the zone temperature sensor
• Liquid infiltration from a boil-over causing sensor short circuit
• Control board fault affecting the temperature sensor circuit

• Do not continue using a zone that shows F5 at startup — a short-circuit sensor cannot provide safe temperature control

F5 appears at the start of a cooking session with no extended prior runtime

• F5 recurs on the same zone consistently

• Thermador induction and radiant cooktops automatically switch off zones after ~2 hours of continuous use — plan cooking sessions accordingly or re-activate the zone at the 2-hour mark
• Clean up boil-overs immediately — liquid under the glass can cause sensor short circuits that trigger F5