DIAGNOSIS Grease accumulation on the interior ceiling and heating element guard is expected. It can cause smoke and odors during subsequent cooks if not cleaned.
FIX Unplug and cool the unit completely. Create a paste of baking soda and water. Apply it thickly to the greasy areas on the ceiling and element guard. Let it sit for 20 minutes. Use a non-abrasive sponge or brush to gently scrub. Wipe clean with a damp cloth. For the element itself, only wipe with a dry cloth.
IF THAT DIDN'T WORK For baked-on grease, use a commercial oven cleaner formulated for non-self-cleaning ovens. Apply only to the cold interior surfaces, avoiding any electrical components or the window. Rinse thoroughly.
HEADS UP Never immerse the unit in water or use a steam cleaner. Never use metal scouring pads on the non-stick interior or on the heating element.