Hansa oven does not heat and displays E03; fan and lights may still work.

Safety first: Disconnect mains power before removing any panels or touching internal wiring.

• Visual inspection of elements: Remove oven racks and inspect the visible bake and grill elements for breaks, blisters, or burn marks. A visibly broken element must be replaced.
• Test elements with a multimeter: Pull the oven out and remove the rear panel. Disconnect the wires from each element terminal. Measure resistance across each element. Typical values are 15–60 Ω depending on wattage. If the meter shows OL (open) or a dead short, replace that element.
• Check wiring and terminals: Inspect the element terminals and connecting wires for signs of overheating or looseness. Tighten loose spade connectors and replace any burnt wires using high-temperature cable and proper crimp terminals.
• Control board relay check: If elements and wiring are good, the heating relay on the control board may not be switching. With power restored and extreme caution (or by a professional), verify whether voltage is being sent to the element when heating is commanded. If not, the control board or relay is faulty and should be replaced.

When to call a technician: If you are not experienced working with live mains voltage or cannot access the rear of a built-in oven safely, contact a qualified technician.