Oven does not reach set temperature, very long preheat time, undercooked food

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

• Check operation in different modes: Test conventional (top+bottom), bottom heat only, and fan-assisted modes. Note which modes heat poorly; this points to the specific element.
• Visual inspection of elements: With power off, inspect top grill/element and bottom element (may be hidden under the cavity floor). Look for dark spots, cracks, or bulges.
• Test elements with a multimeter: Remove rear or bottom panels to access terminals. Disconnect wires and measure resistance. A reading of infinite resistance indicates a failed element that must be replaced.
• Check for loose connections: Ensure spade connectors on the elements are tight and not heat-damaged. Replace any burnt terminals and crimp new connectors if needed.
• Listen for relay clicks: Restore power, start a heating mode, and listen for relay clicks from the control board. If an element tests good but never receives power, the relay or PCB track may be faulty and require board replacement.

Note: When replacing elements on Grundig ovens, match the wattage and shape to the original part number printed on the element or in the user manual.