Why does the center of the heater tube not glow red? Due to the structure of the heater tube, the center remains dark. This is not a malfunction. Related articles I need technical assistance for my BALMUDA product. Who can I contact? How to clean BALMUDA The Toaster? Do you need to put water in every cooking mode? Is there any limitation in size (thickness) of the food? Is there any guidance to install BALMUDA The Toaster?