Hansa oven emits a metallic or electrical buzzing noise when heating.

Safety first: Disconnect power before tightening any screws or inspecting wiring.

• Locate noise source: Run the oven briefly and listen carefully (from a safe distance) to identify whether the noise comes from the back, top, or control panel area. Then disconnect power.
• Tighten panels: Tighten screws on rear and side panels, fan housings, and internal brackets.
• Inspect terminals: Check for loose spade connectors on elements and relays. Tighten or recrimp as needed.
• Transformer mounting: If a transformer on the control board is humming excessively, ensure it is firmly mounted. Persistent loud hum may require board replacement.

When to call a technician: If you suspect electrical arcing or burning smell, stop using the oven and seek professional help.