Oven will not heat, display shows E001 shortly after attempting to start a cooking program

Safety first: Switch off the oven at the circuit breaker and allow it to cool completely before any work. Do not bypass safety devices.

• Power reset: Turn off the oven at the mains for 5–10 minutes, then restore power and test. If E001 returns immediately, a hardware fault is likely.
• Check ventilation: Ensure cabinet cut-outs and ventilation slots above and behind the Siemens oven are not blocked by panels, insulation, or items stored above the oven.
• Inspect cooling fan operation: Start a low-temperature program and listen for the internal cooling fan behind the control panel. If it does not run or is very noisy, it may have failed and caused overheating.
• Check thermal cut-out: Access the top/rear of the oven (remove from cabinet if necessary). Locate the small round or rectangular thermal cut-out on the oven top or rear panel. With power disconnected, test it with a multimeter for continuity. An open circuit indicates it has tripped or failed and must be replaced with the correct Siemens-rated part.
• Do not bridge the cut-out: Never short the thermal cut-out; replace it. If it trips repeatedly, investigate cooling fan and ventilation before using the oven again.