Safety first: Turn off power before inspecting electrical connections.

Step 1 – Check outlet: Ensure the Thermador microwave is plugged directly into a properly grounded outlet. Do not use extension cords or power strips.
Step 2 – Verify circuit: Confirm the microwave is on a dedicated 120V circuit of the correct amperage per the installation manual.
Step 3 – Inspect cord and plug: Look for signs of overheating, discoloration, or loose fit in the outlet. Replace a damaged cord or have an electrician replace a worn outlet.
Step 4 – Internal inspection (qualified persons): Check the line filter, noise suppressor, and wiring at the entry point for loose connections or burn marks.
Step 5 – Professional evaluation: If house power is correct and connections are sound, the internal power supply or control board may be faulty and should be replaced by a technician.

Note: Persistent low voltage can damage the microwave; have an electrician correct wiring issues.

Microwave shows E15 and beeps; display may dim or flicker.

Possible Causes