Oven does not heat properly in conventional or fan modes; E04 is displayed after a short attempt to heat.

Safety first: Disconnect power at the breaker before accessing internal components.

Check the lower element:

• Remove the oven base panel (inside the cavity) if present to expose the lower heating element, or access from the rear depending on the Teka model.
• Inspect the element for visible damage such as cracks, bulges, or burn spots.
• Disconnect the wires from the element terminals and measure resistance with a multimeter. A reading of infinite resistance indicates a failed element.
• Examine the wiring and connectors for signs of overheating or looseness. Replace damaged connectors and ensure tight fit.
• Install a new OEM lower heating element if the original is open or damaged. Make sure it is seated correctly and not touching the cavity directly.
• If the element is good, trace the wiring back to the control board and inspect the board for burned relay contacts or damaged tracks. A defective board will need replacement.

Test: After reassembly, restore power and run a standard bake cycle. Monitor temperature rise and verify that E04 does not reappear.