As a next step, we tried to place only the foil back on the plate. After switching the cooker on, it levitated and this was not caused by hot air! (Remember the school experiment with an aluminium ring to demonstrate Lenz’s law?) When we then held the foil (without cooling by the pot) on the plate, it was glowing white in some places and started to melt and sparkle. It seemed that the thin foil did not load the cooker so much as to switch it off by the integrated protection