Microwave stops heating shortly after start and displays E02.

Safety warning: Unplug the microwave before removing any panels. High-voltage components inside a microwave can be lethal. Do not touch or discharge the capacitor unless you are trained and equipped to do so.

Basic user checks:

• 1. Check ventilation: Ensure the Blomberg microwave has adequate clearance on all sides as specified in the user manual. Remove any items blocking the side, rear, or top vents. Clean dust and grease from the vents with a soft brush or vacuum.
• 2. Avoid running empty: Never run the microwave with no load. Place a microwave-safe cup of water inside and test again. Running empty can overheat the magnetron and trigger E02.

Advanced checks (technician-level):

• 3. Inspect cooling fan: Unplug the unit and remove the outer cabinet. Locate the magnetron cooling fan (usually near the top rear). Spin the fan blades by hand to check for binding. If the fan does not run during operation (test briefly with cabinet loosely in place and all safety covers fitted), the fan motor or wiring may be faulty.
• 4. Check thermal cut-out: Locate the magnetron thermal cut-out (TCO) clipped to the magnetron or waveguide. Test it with a multimeter for continuity. If it is open and does not reset when cooled, replace it.
• 5. Inspect magnetron: Look for burn marks, cracks, or discoloration on the magnetron body and terminals. A failing magnetron can overheat quickly and repeatedly trigger E02. Replacement should be done only by a qualified technician.